When you get a chance; read all the back-posts on this forum. Its a really good place for information. There are a lot of peole here that have a lot of experience.
For my big and small alligator snappers, I use heaters. Depending on your tank size ( I assume its not that big if he's a baby )Get a heater at your local pet store. A light for basking is OK, but you really don't want the light to be the heat source for the water. If the light is close enough to be heating the water; its too close and hot and the animal could be hurt if he comes in contact. The heaters work great and will provide constant even temp.