The Bush Airport is really close to the Testing Center for the CS in Houston; google map estimates 6.7 miles; figure 10-15 minute drive. For my group, the test was done about 3:30 in the afternoon.
There were two hotels I looked at that were very close to the test center--Days Inn and Baymont Inn (they're right next to each other). You can probably check the going rates online to see which one is cheaper. I ended up in the Baymont b/c it happened to be the cheaper of the two at the time. The room was nice, and they offered a free breakfast starting at 6am. Though I drove to Houston, I figured if worse came to worse, I could probably walk to the test center (5-10 minutes) from my hotel.
Definitely show up early, and don't forget to bring everything you need for the CS--Gov't issue photo ID, confirmation notice, scheduling permit, white lab coat, and stethoscope.
Good luck.
