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 Fighter 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. An archer 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 archers can fall back on melee weapons and have higher AC/HP than offensive casters. And casters have very powerful AoE cone attacks very early, it might take an archer 30 seconds to kill 6 grouped Kobolds but a caster may be able to do it with only 1 or 2 spells.