Ars Technica has long been one of the most comprehensive and respected sources for Mac news/analysis.

Daring Fireball when John Gruber has something to say, most of the Mac world stops and listens.. attentively. No joke.

AFP548 Mac OS X Server administration. Not the most lickable site, but their forums are a freaking gold mine.

Make Mac Work administration and implementation of Mac systems in corporate environments. Superb content.

Engadget has tech news and reviews for probably every freaking electronic product you've ever heard of.

Lynda.com online, self-paced video training for pretty much everything (459 courses, 30K videos)

iLounge is the most significant iPod and iPhone (and accessory) site there is. Dizzying number of reviews..

Paul Stamatiou a wealth of comprehensive and thoughtful Mac commentary. Very smart kid.. keep your eye on him.

Tech Crunch a bit sensationalist.. but still have their finger on the pulse of the tech industry