Sent by LeslieEditor: Leslie, congrats on your first herb garden! The good news is, in our experience, herb gardens are really easy to grow and maintain:
First you'll want to make sure their sitting in a well lit window -- southern exposure is best, but any window that gets a long period of sunlight will work.
Second, don't over water the plant. Just like other indoor plants, you'll only need to water the plant about once a week. If you're unsure just stick your finger in the soil about an inch, if it's dry it needs watering! Also be sure to water only the soil/roots not the leave. As with any other plant, if the leaves are turning yellow, you're probably over watering -- make sure your pot has enough drainage and you're letting the soil dry between waterings.
Additionally, be sure to pick the leaves to encourage growth and don't let any flowers bloom. If you see your plants start to flower, pick off the blooms right away, otherwise the plant will put its energy into producing flowers instead of leaves.
Lastly, fertilizer is probably not necessary, but we love Drammatic "K" Earth Friendly Fertilizer for our herb and vegetable gardens -- it's organic, can be used on indoor and outdoor plants, and works like a charm. You may be able to find small containers of something similar, or some really nice garden store or nursery may be willing to sell you a bit of theirs.
Remember, every plant is different, so if you're having any problems just ask your local flower store or nursery for help. Personally, we think the Union Square Greenmarket is a great resource.
Good luck! Does anyone have any other tips for Leslie?