When to Plant Herbs in Spring?

When's the best time to plant herbs? Does the soil have to be wet before planting? Is it better to plant them in the garden or in a pot?

Most herbs prefer the extra room to grow that a garden provides. So, if you have a choice, a garden will give you bigger, more healthy harvests, and generally will require less care than when growing in pots.
As soon as the threat of frost is past in your area, it is safe to plant herbs. For most of the temperate east of North America, the last frost date falls in May.
If the soil is wet (but not soggy wet), herbs and most other plants will transplant better. Transplant shock occurs to plants mainly because the water supply to the leaves has been cut off by the damage to the root system that inevitable occurs when plants are moved. If the soil is dry and not watered adequately, plants will suffer and may perish.