I came across this link to a bird ID poster from the Minnesota Dept. of Natural Resources. The bird call recordings are courtesy of the Cornell Lab of Ornithology...
http://www.dnr.state.mn.us/nature/birds/bird_songs_interactive.html
Thank you for posting this link, Kinderchick. I do not know the bird songs/calls of most birds, so found this very interesting. I would love to get a CD of bird songs/calls but have not yet found one.