I’ve had a subscription (via work; thanks boss-man!) to O’Reilly’s Safari Bookshelf for a couple months now, and I’m starting to think that it’s one of the Best Things Ever. I can read (online) pretty much all the xhtml/css/flash/php/MySQL/security/programming/certification/business logic pr0n I could ever want right there.
While I’m pretty sure they don’t carry a lot of private label training/certification labels, and though it seems like some of the publishers involved (SitePoint, for sure) hold back a few of their publications, I can get both high and mid-level information about any technical (read: computer-related) subject I can think of. Most of the time, I’ve been able to find something to help me get down and dirty, when I need it, too.
So, to recap: Safari Bookshelf = sweet!