Last spring, I decided I wanted to start my first garden. (I ended up planting in pots, but you know. You start where you are!) I found my state's cooperative extension website to be an absolute treasure trove for local information about what to do, what varieties grow best, frost dates, and the like. I highly recommend visiting your state's cooperative extension website. Just google "cooperative extension" and your state's name and see what what you turn up. :-)
This was going to be my recommendation too - but Joyous beat me to it! In addition to helping you plan your garden, you can get information about composting, fertilizing, weed control, and much more from your state's cooperative extension website.
If your state has an agricultural college, that's also a good place to get this type of information.