I hate to ever disagree with my dear old friend lorax ( fingers crossed behind back and grinning ear to ear) but I think I can add a few things for us temperate gardeners based on some success and experience.
I don't often use agristarts since the plants are tiny and not as likely to do well especially for begginers. There's many online sources and one reputable one I can vouch for is Going Bananas in Homestead florida.
The people are knowledgeable and friendly either by phone or email and more importantly you'll get the variety you ordered which isn't always the case with some. I wont name names but I would never buy any plants from anywhere in Georgia that feature bikini clad women more than their plants ( there's better bikini sites I'm sure too if thats what you're after
I can vouch for the fact that anything reputed to be hardy to -20 and edible is a farce and I wouldn't buy anything from that source.
One plant that I'd recommend to all begginers and is seeded but technichally edible is the Musa Velutina ( aka Dasycarpa). I had one flower for me last year in the ground on a first year plant with a two year old corm ( the underground rhizome portion). They produce nice pink colored fruit on a smallish plant and could even be hardy to zone 7 with protection in the right microclimate.
Here's a shot:
Another must have for the northern gardener wanting some edible fruit is the "Veinte Cohol" this one will flower in October from a 2' plant, planted in May ( bananas are measured by the height of the psuedostem... trunk portion ) Since the bananas take time to develope and ripen I think starting with a large plant in spring is best here in zone 6 and I'll be starting with a 4 or 5 ft plant this year so as to expect ripe fruit before it gets too cold out.
Here's a bunch from last year:
Last I'd reccomend the " Ice Cream" aka "Blue Java". This is a larger variety and on its own would grow to a 14 ft or so height and seems unmanageable for most but for the two years prior to flowering I simply whacked the plant down to size with a machete and it started growing again indoors in its pot. Yes you risk the chance of cutting a flower and killing the mother plant but I've known several gardeners in very cold climates who've had success with this reliable cultivar. Here's a few quick shots of this one and I'll end it before I get into a novel and myself in more trouble from one of my initial mentors down under in Ecuador !