Hello and welcome,

I've bought from Bountiful gardens and Baker Seeds - both great. Also, I've traded plants and seeds with locals at Farmers Markets. Look for small local nurseries or gardner groups that sell their plants in the Spring. My first time growing Heirloom tomatoes were from a group that was trying to get rid of their left over plants. Good luck and have fun!

I got my start with the Seed Savers Exchange. You can find them easily by doing a Google search. It was through being a member of that group that I initially made friends with a good many folk who were helping each other along with seed saving. Now, there are more ways to do this. Gardenweb is one of them. But I thought I'd mention it. Seed Savers Exchange has some good educational materials and, many good people.

Here's a link to another good seed company with a good many open pollinated and older varieties:

George

Here is a link that might be useful: Sandhill Preservation Center

So, are you thinking you want to plant a few tomatoes in containers? Or, are you planning on just clearing out a couple of rows? I'm a fan of square foot gardening. Here's the about page: http://www.squarefootgardening.com/aboutus/. If it appeals to you, find the book in your library or online somewhere before you buy anything. There is a shop at the website, but I would recommend starting with a small plot before you buy anything. It's amazing how much you change your mind on things from season to season. The seed places both other posters recommended are places I'm fond of.