To start off, here are some of mine. Since Mac OS X and Apple Hardware are kinda interlinked, some of the sites below deal with both...
About This Particular Macintosh - A webzine of sorts that covers a lot of things and is as good, even better sometimes, than those Mac magazines you get off the shelves. Love the humour.
Apple Legal - Don't know about the name, but this is a software review site for Mac applications. The review quality is pretty good, short, but pretty informative.
MacFixIt - Troubleshooting Solutions site. The recent post on preparing your computer for an installation of Tiger is very helpful.
MacNewsWorld - A collection of Apple in the news everywhere, online and offline, quite interesting to read now and then and really good if you're going to write a paper on Apple and need news sources.
MacOSXHints - A collection of short but sweet hints for the OS, some of which are well-known and aimed towards the beginners, but they have often rather interesting and less well-known hints too.
MacRumors - Rumors site. I got there mostly for the forums though, they have a huge userbase and they are very very helpful when something is happening to your mac and you don't know what to do... Heh.
How about you?

