What is a good book to read to learn about RAC? I am most interested in the practical end rather than the theory behind it.
Check ronr.blogspot.com for a plug of and link to a book by Ben Prusinsky and Syed Jaffar Hussain that is very practical. It explains lots of things, and how to do them in great detail. There is lots of hands on experience in it. Very - VERY - nice.
In addition to the suggestions already posted, I highly recommend the Apress edition for 11gR2. I used it extensively to implement our development and production RAC environments after having no previous experience on RAC. Hope this helps!
Here's a link to the book on Amazon