Tim, here's a suggestion for your library, although I won't get the title exactly right (my copy is in the trunk of my car, and it's snowing out, so I'm not going out to get it):
A Photographic Guide to the Hawks/Raptors of North America, by Clark and Wheeler (softback, around 21.00).
This is a very comprehensive guide, jammed full of photos, to all the raptors you'll find in North America. The species account is skimpy, but that's more than made up for with the photos. Each species is documented with an average of 15-20 photos of both sexes, all ages, all plumages (including geographic/racial variations). It's a really terrific guide and should be very helpful to you on raptor ID.
Wheeler and Clark have now come out with a 3-volume hardback raptor guide that I've only glanced at, but which expands greatly on their original guide. This set DOES include all the species account info you could want. I saw this set given as a gift to someone else, and I'm guessing that it's around 20.00/volume.
(But I'm gonna have to have it, eventually!)
That's a very vital information, since I could mistake it for other hawks.
