So the first thing I got when I wanted to start birding was a book. I bought one of those little Audubon mini-books with full-color photos of birds of the East (I live in Central Pennsylvania). I definitely prefer color photos rather than the color illustrations.
I used that for a couple of years--not much variety in that book, and certainly it's more of a "oh, I saw that bird the other day! That's what it's called!" kind of book. I realized I needed a true birding book.
At a local charity booksale, I found a copy of Roger Tory Peterson's first book--for only a dollar. It was first printed in 1934! It's an incredibly easy to use, helpful book. Lots of illustrations (what do you expect for 1934?), descriptions of the birds, key identifiers of different types of birds, transcriptions of bird songs, etc. The book has been very helpful.
I've been told by a real birder that I need to get the newest edition, but I'm kinda attached to my old little hardback guide. Still, I suppose next time I'm at the bookstore, I should check out the new one. Probably has lots of photos and stuff. I wonder if Peterson is still alive.
I've heard of other guides--Sibley's, the Stokes'--but I'm partial to Peterson's.