Your seedlings will have to be "hardened off" before you can plant them outside. Basically you start off by keeping your plants in a sheltered location. Then you increase the amounts of time outdoors while giving them less and less protection. This allows them to get used to the sun, wind, and rain a little at a time and gives the plant time to become strong enough to handle all of these without keeling over. Any vegetable gardening book will cover this process in depth.

By the way, us northerners have to be hardened off too after a long winter else the sun will fry us to a crisp! ;)

As far as the others, I like to sow the seeds for basil and cilantro in situ, meaning directly in the bed where they will be growing. I've had the best luck that way.

As far as when to plant outside, whenever people are planting sweet corn and tomatoes in your area. That generally the right time for planting your seeds outdoors.

FataMorgana

Cilanto needs direct planting in outdoor soil. It doesn't like a lot of heat or strong sun. Bolting of cilantro is when the leaves change shape, from their common parsley shape to a fern like leaf. These fern leaves are ok to eat, but their stems are tough. Next come flower clusters, similar to dill. The flowers die out and in place, the 'fruits' are formed as little green balls, which ripen to a tan color. They can be pulled off, or allowed them to drop where they are. New plants can emerge, but if the heat is too much by that time, it may be better to collect the seeds and plant in cooler weather. If you want a continual supply, successive plantings are necessary, as they seem to mature to the parsley shaped leaves all at once. Because your in Z7/8, it may be bit late for cilantro right now, unless the next 50-60 days are going to remain cooler. Not sure when your last frost is (if any), but you could plant at that time, as most seeds will survive a few frosts. Plant them close together for easier harvesting.

Bolting is always the trick with cilantro but the soil temp needs to be 55-68 degrees F to germinate. The plant tolerates much cooler temperatures (it was green most of the winter here) but it requires the soil temps noted above for germination.

If it does bolt, the seeds are used as a spice and called coriander. Pretty flowers and seed heads.

FataMorgana

Here is a link that might be useful: Growing guide for cilantro

As you are hardening off your catnip seedlings, be sure to put them where cats can't get to them, or cover your container with chicken wire or set them in a hanging basket. Otherwise, they will be chewed or rolled on. You want to give them a head start in order to survive future abuse ;D