Once danger of frost is past in your area, sow thyme seeds outdoors in a sunny location. I have grown thyme in pots before, and it does well. You will want well drained soil. For an earlier harvest, plant seeds indoors 6-8 weeks before last frost date in your area.
To harvest thyme leaves, just take as needed, or cut the flowering tops in the summer, for drying.
Seeds will germinate in 7-14 days. Plant the seeds about 1/4 inch deep, and space them about 8 inches apart. They will grow to about 12-18 inches, and are a perennial.