I would like to create a ranged damage dealer. Should I pick a Ranger or a Sorcerer?

As the spellpoints don't get back just by sitting and waiting (as in some other games) resource management is important for a caster. If you are looking for a class that makes high ranged damage "all the time" you should look at a Ranger specialized in using ranged weapons. A Sorcerer specialized in damage can make a lot of damage. But he needs to select carefully the times he uses his spells, as his spellpoints are not unlimited. i.e. A ranger provides constant ranged DPS (though as opposed to PnP keeping distance from mobs wildly running around is very hard) a sorcerer or mage provides higher DPS but with a limited amount. Secondary considerations are that rangers can fall back on melee weapons and have higher AC/HP than offensive casters. And casters have very powerfull AoE cone attacks very early, it might take a ranger 30 seconds to kill 6 grouped Kobolds but a caster may be able to do it with only 1 or 2 spells.