Very true, Byrd!

But when you're buying seeds, you might want to skip most of the ones in the racks at the local stores (there are some exceptions), as their germination rate isn't usually the best, and some of the stuff doesn't grow well under your local conditions.

Get some of the better seed catalogs and study their plant descriptions. Some varieties are best for northern or southern gardens, some store very well and others are better to eat right away, some are hybrids (you have to buy more of the same kind of seed to get the same results because they don't 'breed true') and some are open-pollinated (OP) that you can save the seeds from, once you learn how. Some plants are better for growing in fall/winter in milder areas or in an unheated greenhouse, and others will simply croak.

Some good seed and plant catalogs that I have seen:

Territorial Seed www.territorialseed.com
Bountiful Gardens http://www.bountifulgardens.org
Johnny's Selected Seeds www.johnnyseeds.com
R.H. Shumway www.rhshumway.com
Nichol's Garden Nursery www.nicholsgardennursery.com
Raintree Nursery (food plants) www.raintreenursery.com
Burnt Ridge Nursery (food plants) http://www.burntridgenursery.com/
Seeds of Change www.seedsofchange.com
Pinetree Garden Seeds www.superseeds.com
Bear Creek Heirloom Seed www.rareseeds.com
Vesey's Seeds www.veseys.com
John Scheeper's Kitchen Garden Seed www.kitchengardenseeds.com
Vermont Bean Seed Co. http://www.vermontbean.com/
Fedco Seeds http://www.fedcoseeds.com/
Filaree Farm (lots of garlic) http://www.filareefarm.com
Heirloom Tomatoes http://www.heirloomtomatoes.net/
Landreth Seed Co. http://www.landrethseeds.com/
Native Seeds/SEARCH http://www.nativeseeds.org
Ronninger's Potato Farm http://www.ronnigers.com/
Sand Hill Preservation Center http://www.sandhillpreservation.com/
South Carolina Foundation Seed Assoc. http://virtual.clemson.edu/groups/seed/heirloom.htm
Southern Exposure Seed Exchange http://www.southernexposure.com/index.html
Victory Seeds http://victoryseeds.com/

There is also the Garden Watchdog service, that rates sources of garden seeds and equipment: http://davesgarden.com/products/gwd/