A friend of mine is teaching a course in Digital Imaging and Photography this semester and asked for suggestions for a list of related resources she's compiling, and of course my first thought was that you folks would have all sorts of things to contribute, so:
What are your favorite resources?
Which books or sites do you turn to when you want help improving your photographic and digital techniques?
Is there a particular Photoshop tutorial that became part of your workflow?
A photo that inspired you to try something new?
Entry update
Cameron set up a wiki page so please consider leaving your responses there:
http://wiki.photoblogs.org/Indispensable_Resources%2C_Books_%26_Tutorials
A couple to start:
The Ansel Adams Photography series and London & Upton's Photography textbook.
Luminous Landscape's tutorials and Understanding... series.
photo.net's Learn Photography section (the forums are great, too, but can be a bit overwhelming).
The Compositional Dos and Don'ts article here awhile back has some great (though contradictory!) advice.
Flux + Mutability highlights a wide range of (mostly modern) photographers.
(and a little self promo: I keep a links blog of photos and tutorials and other things I find useful when I'm feeling uninspired.)
