Length of incubation of eggs

Question
I have a group of the Texas Spiny Lizards (five to be exact) and two of the females just laied eggs, but I have been unable to find information on how long the eggs will be incubated, or what tempeture the soil needs to be. Can you tell me how to take care of them?

Answer
Give me the details listed in my instructions first.

Are these wild Texas Spiny's that were caught? Where were the eggs laid? Is this indoors, or outside somewhere? What kind of soil? Have you moved them at all, or messed with them so far?

"taking care" of them is a little detailed. I need to know what is going on first, because I don't even know if this is something you found, or lizards were previously in a terrarium.