Suggest you contact your county's Extension Service Office and ask to speak with an extension agent who can help you with the needed info.

Use this interactive map
http://www.csrees.usda.gov/Extension/

Here is a link that might be useful: locate your county's Extension Service office

Sunnyday - Where are you located? I am wondering what nursery is operational in January around here. It is March now and I still have plants encased in ice outdoors at my nursery.

I think the most important criterium in selecting plants to grow is figuring out what isn't readily available or is in short supply. There are certainly a lot of things you could grow, but growing on a small scale, you won't be able to compete on price with the big nurseries and chain stores. If you are growing from seed, there are a tremendous number of annuals and perennials that you can start that are not commonly available. This will take some time, visiting stores and farmers' markets, to see what is being offered and at what prices. The other approach is to grow plants you like yourself with the assumption that other people will like them as well. Good luck!
P.S. Happy birthday.