This is a very good article explaining Congenital Adrenal Hyperplasia. It even has drawings showing where the adrenal grands are located, and explains the adrenal-pituitary thermostat control. The article is very informative.
An explanation of what congenital adrenal hyperplasia (CAH) is can be found here. It covers topics such as classic CAH-21-hydroxylase deficiency, nonclassic CAH-21-hydroxylase deficiency, diagnosis and treatment.