Is there only 1 hide in there. You should have one on each side. As to putting the bulb on the glass I woudln't do that. I'd suspend the light above the tank, a few inches will make a big difference.
You can get something like this:
http://www.petco.com/product/5011/Zo...amp-Stand.aspx
These are the lamps I use, which have built in rheostats:
http://www.petco.com/product/116922/...plies_Lighting