Are there any good books about X and Gamma-astronomy? I'm writing an essay about Cosmos seen in these rays but searching Internet brought me just tons and tons of articles with so complicated and tight explanations that confused me more. Anything?

The website on the Chandra X-Ray Telescope has some good educational resources. I've seen a book on X-ray astronomy at a bookstore, but don't quite remember its name. Sorry.

Thank you. I visited the site and I found it quite good!