In my search for seeds and seedlings online (because nothing was available locally), I came across 2 companies that had excellent ratings and variety:

Burpee had the most robust and interesting varieties of herbs, vegetables and flowers; and I like the company’s storied history. Reasonably priced as well. They also deliver seedlings as well as seeds and sell excellent seed starting systems:

http://www.burpee.com/

Seeds of Change is an good certified organic option:

http://www.seedsofchange.com/