Online books
Sijin Joseph give me some good infos on Safari and Cathal refer also to another service that look quite good too.
I'd recommend books24x7.com . They're a little bit more expensive than safari at $300/year for the ITPro section, but have a very large collection of books, including their own material, and are continually adding books.
They've a trial, that gives full access, but obfustacates content so you can get a feel for it.
[ Cathal ]`
Thanks for this link, I just regret that they don't have a full free trial test. When I registered the content was masked.