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.comBountiful Gardens
http://www.bountifulgardens.org Johnny's Selected Seeds
www.johnnyseeds.comR.H. Shumway
www.rhshumway.comNichol's Garden Nursery
www.nicholsgardennursery.comRaintree Nursery (food plants)
www.raintreenursery.comBurnt Ridge Nursery (food plants)
http://www.burntridgenursery.com/Seeds of Change
www.seedsofchange.comPinetree Garden Seeds
www.superseeds.comBear Creek Heirloom Seed
www.rareseeds.comVesey's Seeds
www.veseys.comJohn Scheeper's Kitchen Garden Seed
www.kitchengardenseeds.comVermont 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.htmSouthern 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/