Rogue is an assassin, attacking from the shadows with his deadly daggers. While TR does have some ranged skills it's a melee class with decent amount of Crowd Control skills.
Main Ability Scores of Rogue are Dexterity, Strength, Charisma. His tactic skill is Shift allowing Rogue to do acrobatic rolls.
Rogue have specific class mechanic: Stealth. He can disappear in shadows if stealth meter is filled so enemies won't see him. While in stealth mode most of his skills gain additional abilities. While stealth meter won't regenerate while in fight there are some talents and skills that can refill it.
Best classes for Rogue are Halfling, Half-orc and Drow due to matched AS.
Effect of Ability Score on stat per point over 10:
Combat Advantage damage
Damage Over Time (DoT) resistance
Area of Effect damage resistance
Companion stat bonus