We like to start our tomatoes indoors, from seed, about six weeks before they will be planted into the garden. For us in zone 8b, we will plant tomatoes in the garden around the first week of May, so we start our plants around March 15th.
For starting our tomatoes indoors, we use a store bought organic potting soil. We start the seeds in small trays, and keep them in the warm house until germination occurs. Then we move them out under fluorescent lights in the garage. We will also transplant them up to 3″ pots after 2 or 3 weeks.
See the video below for a demonstration of starting tomatoes. Please let us know in the comments if you have any questions!