Well, I might as well add in my free documentation here, now that we have a proper place for it.
A year ago or so I wrote a rather long documentation for the "ABC" range of AVR boards manafactured by Austrol Pty Ld. Both boards are based on the (now aged) AT90S8535.
The manual contains many AVR-related topics and explanations not limited to just those boards on which it is focused. Most if not all of the peripheral, register sections are applicable to all AVRs and so those new to AVRs might want to check it out.
I welcome all feedback on it. It's not a great literacy work, but I certainly put a lot of effort into writing it all those months ago. You can view the documentation at http://fourwalledcubicle.com/ABCmanual.php.
- Dean :twisted: