I just came across this online book: http://www.digitalbirdphotography.co.../contents.html It is the most complete, in-depth resource I've ever seen to digital bird photography. It is over 900 pages long, and using it is free! I think anyone at any level will find it fascinating. The author WH Majoros, is a scientist and he's also written many other publications about biology and birds. He looks like a pretty cool guy.
I have known about this site for some time, and I agree it's great - full of good info., and the price can't be beaten! Most of the info. is also available here in BPN, although a lot of it takes some searching, and it's not in such an integrated and all-inclusive form.
Having just registered on this site with the intention of improving my Avian photography and post processing skills I find this thread and the link it contains to "Secrets of Digital Bird Photography" invaluable and a fantastic resource tool. Many, many thanks.