I agree with timmcowan.
I read the "Professional SQL server Reporting Services" book by Wrox first. It was a great introduction - very fast read. I recommend this one to get up to speed.
I then purchased "The Hitchhikers Guide to Reporting Services" and I found that it was more detailed and has some very good "how-tos" on installing reporting services with great detail on security. I liked this book the best so far & I am only half way through it. I recommend this one also to get into more details.
I started some development after the first book. Deployed a few reports to our test server and showed the CEO. He liked it so much he approved a purchase for a new sql server dedicated to reporting services. However, since I deployed those test reports, I have been inundated with requests to convert our existing reports and have not had any time to get back to the Hitchhikers Guide.