Marksman Hunter is a top ranged DPS on WoW Wotlk, with good sustained damage and some burst damage, however, in high mobility fights its DPS can drop considerably depending on how good the player is.

Rotation for Marksman Hunter Wotlk

Marsman Hunter Rotation and Priorities

Hunter’s Mark (Keep debuff up) > Serpent Sting (Keep debuff up) > Chimera Shot > Aimed Shot > Steady Shot > Arcane Shot > Spam Kill Shot on low Health

Tips

Get to know the fights to pop cooldowns at the best times (low movement, no crowd control, AOE, etc).

Time cooldowns so they can be used to clean thrash and be ready for a boss fight.

Use Volley and Multi-Shot in AOE situations.