You should plant your tomato seeds indoors. Sowing tomato seeds is NOT recommended. I usually plant them in peat pots or plastic cups I save from eating out. You'll get some pictures of that as the weeks go by. I'll be planting a second crop of heirlooms because I got a few with my seed kit that I've never tried before and am excited to see how they produce. And the photo is actually of a Black Krim tomato plant I have growing right now. At about 1 foot tall you should stake or cage your tomatoes, I'll post photos of that in about a week from publish.
Keep checking back on this instructable! I'll be posting more and more as the weeks go by!