Eviscerate (Finishing Move) - Finishing move that causes additional damage per Combo Point. This is your instant damage SLAM ability that you should use to finish monsters off or take a chunk out of them. Manual of Eviscerate (Rank 9) drops off Blackhand Assassins in Black Rock Spire.
Garrote (DOT)(Requires Stealth) - Garrote the enemy, causing X damage over Y seconds. Must be in Stealth mode behind the target. If you are going to fight the target for a long time it's a wise idea to sneak up and use this skill. The monster will be damaged over time as you fight them. Garrote increases in potency with greater attack power.
Rupture (Finishing Move)(DOT) - Finishing move that causes damage over time. Lasts longer per Combo Point. This is another damage-over-time ability that is more useful when you fight the monster long enough so that it reaches the full effect; otherwise, you should use another finishing move. Rupture increases in potency with greater attack power.
Ambush (Combo move)(Requires Stealth)(Requires Daggers) - Ambush the target, causing X% weapon damage plus Y to the target. Must be Stealthed and behind the target.
Slice and Dice (Finishing Move) - Finishing move that increases melee attack speed by X%. Lasts longer per Combo Point. You only need to power up this ability enough such that you have the increased speed for the duration of the fight. If you are fighting multiple monsters you might find it useful to power-up on one monster, release, then use the speed on the second monster. This can trigger the Ruthlessness talent.
Cheap Shot (Combo Move)(Requires Stealth) - Stuns the target for X seconds. This ability allows you to start off the fight with some cheap hits on the enemy that they can't respond to. A Rogue could also Stealth during a fight using Vanish (while in a party) and use a Cheap Shot at the end of the fight to prevent the monster from escaping.
Kidney Shot (Finishing Move) - Finishing move that stuns the target. Lasts longer per Combo Point. This ability can also be used to stun a monster to prevent them from escaping or to prevent any further damage. This is subject to diminishing returns.