Starting a Fighter

Fighter Styles
The Fighter class gets an amazing number of feats - more than double of any other class, which lets you customize your build to get exactly what you want.

Sword & Board (Stalwart Defender and Vanguard)
This is the least common style of fighter, most likely focusing on the Stalwart Defender enhancement tree. The shield gives the fighter an amazing boost to his Armor Class and other defenses, which allows him to take a lot more abuse in melee combat than a fighter without one. However, those defensive benefits come at the loss of DPS. When weighing the damage capability of two-weapon and two-handed weapon fighters, the sword and board fighters come off as weaker. The logic used being "If it's dead, it won't hit me back." This style is, however, quite useful to switch to when tanking - more AC and DR from shield-blocking will help mitigate damage. It is not recommended for new players to attempt tanks if they have not done extensive research. It requires you to know where to pick up all the loose ac you can and is very difficult to tank difficult content with a proper build. However, dedicated tanks can be a massive boon to their party, especially on higher difficulties where weaker party members can become decimated from enemy attacks that a tank could easily shrug off.

Conversely, a build utilizing the Vanguard enhancement tree provides a balance between offense and defense. Such a build combines the defensive benefits of equipping a shield with the offensive power of passive shield bashing and increased attack speed and mobility as well as crowd control capabilities in the way of stuns (including what could be said to be the strongest stunning ability in the game) and knockdowns. While it does not give the same defenses of a dedicated tank or the offense of a dedicated two-weapon or two-handed fighter, it is nonetheless a strong compromise between damage and survivability and quite beginner friendly.

Of minor note, the term 'Sword & Board' usually refers to any shield-bearing melee build, but that does not lock the player into only using swords as a weapon.

Two-Weapon Fighter (fighter kensei)
Although two separate styles, they are actually very similar. The lack of a shield means that you're down at least 7 AC at higher levels; however you can make up for some of it using the Shield spells, which grants 4 AC, and is castable by a wizard or sorcerer (on themselves), or by a clicky.

A Two-Weapon Fighter specializes in dealing damage to a single target. You get more attacks per round and get the modifiers from two weapons.

Currently, Two-Weapon Fighters (or TWF as it is often referred as) are one of the most efficient melee damage dealers and is a choice recommended by many players. (once a two handed fighting barbarian surpasses 90 strength two handed fighting begins to deal more damage, when that isn't happening two weapon fighting is top tier damage per second) It is also recommended not to play two weapon fighters as a new player for several reasons, most notably that you must have 17 dexterity for all of the feats, which will force you to sacrifice some constitution and strength to achieve if you do not have 32 pt build and expensive +2 tomes. Secondly until you get all three main two weapon fighting feats two weapon fighting takes severe damage penalties. In addition two weapon fighting is more reliant on its feat than two handed fighting and will have visibly large penalties until you take the final two weapon fighting feat at level 11.

Two-Handed Fighter (fighter kensei)
A Two-Handed Fighter is able to deal an impressive amount of damage. In addition to having the most damaging weapons, they also deal glancing blows. The drawback to this style is that lacking a shield is even more apparent, as your glancing blows will be drawing more hate from creatures. If you go this route, you will need to put more emphasis in constitution than a two-weapon or sword-and-shield fighter. This is the easiest style of fighting because you can maximize your strength and still have high constitution.

Recommended Races
Half-Orc: have high strength and bonus damage with two handed weapons, they make great fighters.

Human:Great for the new player or the veteran, extra healing amplification, up to +3 to stats while an action boost is active, up to +6% extra glancing blow chance. They make very good fighters. While the extra feat is not a must have is still nice  and a greater heroism SLA if you have some points to spare in the racial tree.

Dwarf: a sturdy race suitable for tank role. Has bonuses to combat DCs of things like Stunning Blow; also bonuses to using axes.

Halfling: with a penalty to strength, they are rarely the first choice. Higher dexterity makes it easier to qualify to two weapon fighting feats. Can spend AP for saves and sneak attack.

Warforged: tanky like dwarfs, but, in addition, trade 35% of their health gained from healing spells for greater crowd control reduction on themselves and immunity to hold person, fatigue and more.

Strength
Your Strength modifier is added to your damage rolls and your attack rolls, making Strength an important attribute for a fighter who intends to kill things. Even if you intend to function as a tank, don't skip this attribute. Without the ability to deal damage you wont be able to hold on to aggro effectively. It is suggested you raise this the highest you can. You should have 32 point build to sacrifice if you want to play a two weapon fighter or tank so that you do not have to sacrifice damage.

Dexterity
Your Dexterity modifier is used to decide your dexterity bonus to your armor class. Since in full plate your maximum dexterity bonus is 1, the highest dexterity modifier most people get is 1. Fighters can get an enhancement, Fighter's Armor Mastery, which increases the maximum dexterity bonus you can achieve, so if you intend to use this enhancement you should plan your abilities accordingly. Dwarves get a similar racial enhancement, which stacks. Mithral armors with Nimbleness will also increase the maximum dexterity bonus. A dwarven fighter in Mithral Full Plate of Superior Nimbleness can apply an amazing amount of dex bonus to his AC.

Your Dexterity modifier also applies to your reflex save.

The Dodge feat requires a minimum dexterity of 13.

If you take Weapon Finesse, you may add your dexterity modifier to your attack rolls instead of your strength modifier for light weapons, rapiers, and unarmed attacks (with or without handwraps). Your full DEX bonus is applied even in heavy armor. Weapon Finesse is rarely recommended for fighters.

If you plan on going the TWF route, make sure you have enough dexterity to take the Two Weapon Fighting feat (DEX 15 required), as well as its successors (DEX 17).

Note that in harder dungeons a "medium" amount of reflex saves and ac may do little to nothing, and the points may have been wiser invested into strength or con. Unless you know you can get a healthy amount of ac or reflex saves you should only take enough dexterity that you have to.

Constitution
Your Constitution gives you a bonus to your hit points, as well as bonus to your fortitude save. For every point of constitution modifier, you gain one additional hit point per level. 14 to 20 constitution is suggested. Less constitution is not recommended.

Intelligence
Your Intelligence decides how many skill points you get. Other than that, the only reason to get INT is to fulfill a prerequisite for a feat - commonly, Combat Expertise which requires 13 intelligence. Other than that, Intelligence isn't very necessary.

Wisdom
Your Wisdom modifier is added to your will saves. Other than this, pretty much completely useless for a fighter. While will save is your weak spot, investing in Wisdom is not recommended.

Charisma
Fighters can use a higher Charisma mainly to raise their UMD skill (if they plan to focus on UMD), and their intimidate skill, which can be very effective to hold aggro. Intimidate is useless outside of tank builds, but UMD is one of the most powerful skills in the game. UMD allows for self buffing, self healing (between fights, or during kiting if HPs get low), and allows a degree of self-sufficiency not possible in a fighter without UMD.

28 point fighter
You could attempt a two weapon fighting character independent of 32 point build but you would sacrifice damage. It would be much more effective to play a less point starved dps style.

Str: 18 +4 to hit and damage (Value Odd numbers, they mean earlier advancement and flexibility)

Dex: 8 -1 tanks can invest in this heavily for defense. Two weapon fighters should take the minimum requirement they need (note that if you have access to a +1 dex tome you can take 16 dex and you can take 15 dex if you have a +2 tome of dex (+1 and +2 tomes can often be found in the Auction House or be received by reaching 1,750 Total Favor)

Con: 16 +2 to HP/level and Fortitude Saves

Int: 8 -1 some tank feats require a 13 Int

Wis: 10 +0 there is little you can do with your starting stats for Will Saves as a fighter for wisdom saves, which wisdom boosts.

Cha: 8 -1 useless outside of specialized tank builds

Recommended Class Progression
If you are going two-weapon fighting you can either use a shield or a two handed weapon until you are confident in your TWF dps.

Recommended Feats
Depending on your fighting style you can take, the three two weapon fighting feats (you won't need oversized two weapon fighting) and can get at level 1, 6 and 11. The three two handed fighting feats are less important early game so you can take them at late levels, tower shield proficiency is auto-granted to fighters, useful for  tanks.

Toughness: you can take this anywhere from once to seven times as a fighter. Take it only if you have nothing useful to take or if you have low hp, it adds 3 hp at first level +1 hp every level beyond first (for a total of +32 hp at level 30).

Weapon Focus (Slashing): take either level 1 or 2. take the feat "Greater Weapon Focus: Slashing" at higher levels

Weapon Specialization (Slashing): must have at level 4 to qualify for Fighter Kensei

Improved Critical (Slashing): a must have at level 8

Power Attack: take at higher levels when you are confident you are hitting everything on all hits. A must have for endgame dps.

Improved Sunder: and

Stunning Blow: tactical feats are very useful and they can increase the dps on that target significantly by everybody attacking it. As a fighter you should seriously consider taking one or both of these.

Exotic Weapon Proficiency (Khopesh):

Khopeshes are the best one-handed weapons in the game due to its unique critical profile.

Exotic Weapon Proficiency (Bastard Sword) or (Dwarven War axe): This two weapons don't have the great  critical profile of the Khopesh but when wielded by a proficient user as a Single Weapon or Sword and Shield will now produce Glancing blows on enemies around the wielder. The glancing blows are increased by Two Handed Fighting feat chain and enhancements that increase the effectiveness of them.

Precision:  This stance is exclusive with Power Attack, but it reduce the target's fortification against your attacks by 25%. May be worth considerate it if for endgame boss fights, fighting undead or if you don't plan to use improved power attack from Legendary Dreadnaught all the time