You may also want to check out Weiser Airpark which is about 8 miles up 290 to the NW of Houston. There was a place called Ray's Flight Training from which I did some rental's a few years ago. Last time I was there, it looked as if they were no more, but I spoke to some guys from Windsock who now oocupy the premises and they were really helpful. Next time I return to Houston, I am going to fly from there.
http://www.flywindsock.com/