Rangers are sort of a cross between a fighter and a druid.  Rangers are the best class at using a bow, and the best magic bows in the game can only be used by a ranger.  Also, Rangers have an innate resistance to the elements, getting +4 to both fire and cold resistance.  Tracking makes this class really shine.  This skill makes Rangers welcome in any group hunting outdoors.  Foraging is also a nice skill given to Rangers.  If you have a Ranger you can find the monsters that give you the best experience or gold without a lot of mindless wandering, and you can keep a look out for the ones that will kill you on sight.  Rangers are also pretty good fighters and can readily play the tank.  You can't dish out or take as much damage as a warrior, and you are somewhat limited in your weapon and armor selection, but you can definitely hold your own.  Because of his druid and tracking abilities, the Ranger is pretty good solo class.  Tracking lets you pick your fights and only engage the monsters you can beat, and warns you when you are getting near something that can take you out in a hurry.  Your spell casting lets you slow down the foe to better attack or run.  Your ability with the bow gives you the chance to do damage without engaging.  And your fighting ability lets you fight it straight up when you need to.

Ranger Resources: