There is no single most good book of that type.
The <a href="http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=0%2D394%2D50760%2D6" target="_blank">NAS Field Guide to North American Trees, Eastern Region</a>, mentioned already, is okay, but there are a lot of trees in it which you'll never see where you are. And identifying trees with the book is much like navigating many web-sites these days where you must wave your mouse pointer around wildly to see if anything is a link or not. Sometimes called mystery meat navigation.
Peterson Field Guides has a couple out for the region. The older one is for <a href="http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=0%2D395%2D35370%2DX" target="_blank">Trees and Shrubs</a> and does not have the fancier illustrations of the newer one which is for trees alone. I very much prefer the first one and actively chose it over the other due to its more complete descriptions and extensive identification keys system.
Perhaps the closest thing to a best single book is the old standby <a href="http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=0%2D486%2D20395%2D6" target="_blank">Trees of the Eastern and Central United States and Canada</a> by William M. Harlow. It's not nearly as comprehensive in terms of sheer numbers of trees covered, but the ones it does handle have much more comprehensive coverage.
A very good, though somewhat less extensive in terms of tree types as any of the others (all small format volumes), is the large format <a href="http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=0%2D688%2D05039%2D5" target="_blank">The Tree Identification Book</a>, which has (though black and white) extensive photographs showing leaves, twigs, fruit, bark at various ages/types, winter "dress", etc. Per the introduction:<blockquote>"The aim of this book is to present, visually, details of trees essential for practical identification, which in turn leads to tree recognition. The distinction between tree identification and tree recognition should be clearly understood at the outset. Identification is based on observation of details. Recognition means knowing trees at a glance, just as one recognizes one's friends."</blockquote>
Any decent-sized Barnes and Noble will have most of them. Probably not the Harlow one (which you should order if they don't have -- you'll want at least <i>it</i>).
My other current favorite is likely of no use to you there, but the Indiana University Press put out this spring the (although Chinese-made!) most excellent <a href="http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=0%2D253%2D21694%2DX" target="_blank">101 Trees of Indiana</a>. As the title implies, it only covers trees native to the state. Perhaps a university or similar has published something pertinent to your area?
Good luck in your search!
Glen