Warriors are a simple class. You point, you hit. Since they can use any weapon, they don't learn skills the traditional way (that is, by talking to the trainer), they just innately know how to use their weapon in new, stronger ways.
In general, two-handed weapons will do the most damage, but carry defensive penalties (such as not being able to use a shield). One-handed weapons do less damage, but they offer the ability to hold a shield. Alternatively, you can dual wield some weapons to deal more damage. Additionally, halberds will let you hit from up to one tile away from your target.
As warriors level up, they'll gain a lot of hp (compared to other classes), and they also gain offensive and defensive bonuses every 5 levels.
charge- at skill 7 (11 for any other class), you learn to
chargewith any weapon. This lets you run towards a target and hit it, instead of having to be near it.
throw- you can
throwany item at a target. Some weapons return when you throw them, making them excellent candidates for ranged combat.