Ok. What state? I would really, really recommend a state-specific field guide for sure if you are beginning. The general “Eastern US” will include, say, Georgia and Florida, which can mean you’ll be thumbing through a lot of unnecessary pages to find a bird in your back yard in Pennsylvania or somewhere. 🙂 A good set of CD’s for identifying song is a good idea, but I’d not just pop the tape in at first. What you really need to do is first identify what birds you might be seeing and hearing, and then listen to THOSE sections on the CD. You need to be aware that for most species, there is more variation in song than in appearance. If I, for instance, were dropped into PA I’d be able to visually identify a Northern cardinal. However, if the songs on my various CD’s is typical, I’d have a much harder time identifying a cardinal by the song. My cardinals sound VERY different from the ones on my CD’s.
Also, personally I prefer the Audubon bird guides to the NG ones.
When I am trying to help my kids ID a bird, I ONLY give them the state-specific guide. It is just too frustrating to them to be handed a guide with 500 birds in it. This is Iowa. They are not going to see 500 birds. 🙂
Also, you might consider a general backyard bird guide. One I like actually lists the birds you are MOST likely to see at feeders and in towns/suburbs/along roads in various sections of the country. It is called The Backyard Bird Lover’s Field Guide (although it isn’t strictly a field guide) by Sally Roth.
I’ve read my kids bios of Audubon, but I want to warn you. Mine all became furious and/or inconsolable when they found that Audubon SHOT his birds. Lots of birds. I wish, in retrospect, that I’d either skipped that part, or waited until they were older. They were apparently traumatized as they won’t have a thing to do with the man now. LOL