Answer: I think you will like the Plant Finder from the Kemper Center at the Missouri Botanical Garden. You may search by common name or Latin name and each entry includes growing information as well as (usually) a picture. You may need to cut and paste the url into your browser to make it work correctly.
It is not divided by zone, but the zone information is included in the descriptive information. Your county extension may also have some reference materials tailored to your area. Finally, your library may have some useful books. Michael Dirr has written some good ones about trees and shrubs.
Q&A Library Searching Tips