beginner's tactical on tuesday nights at shiloh. sort of like a intro to IDPA.
advance tactical workout hosted by Comp-tac victory gear on wednesday nights at shiloh. Gregg Garrett and Gordoan Carol do have private leassons/classes of their own. Brian Hoffner has a few things going on at various ranges throughout the houston area. John Farnam is having a class in october and november.
Larry Vickers of Vickers Tactical Vickers Tactical This guy should be on everyone's training short list. The classes are expensive but, this is pretty much the highest quality instruction you can get. Larry is a former member of a tier 1 military SF unit (look at his site, you'll see what I mean), so basically you will get the best of the best. You really can't ask for much more than that.
There are many other great instructors out there. Those are just a couple I remembered off the top of my head.