There's a wealth of photography information on the Internet, so much so that it can be hard to sift through to find the good stuff.
Good tutorial videos and other material, free eBooks & tutorials
Serge Rameli. Engaging video tutorials, sells more in-depth DVD based content & workshops
Andrew Gibson. Congenial email list & some great eBooks
Jared Polin. More on the commercial side, but some good basic no nonsense advice, lots of Youtube videos
Chris O'Donnell. Good eBooks, interesting style
Non technical podcast on the artistic side of photography. Great resource if you know you're f-stops from your ISOs & are fed up of retreading the same info on the internet
Jimmy McIntyre. Tutorials & Luminosity Mask information & Photoshop Plugin