It's not so important to have the temperature rigidly regulated as it is to never let the soil mixture become chilled. Keep it around 20 to 24 if you can. Let those seeds think it's growing season!

As a rule of thumb, once you've moistened a seed, never let it stay wet and never let it get dry; there's a wide range of good and acceptable water levels in the term "moist". It's not necessary to cover with plastic unless you're having problems maintaining that moist condition.

Check out all the FAQs over on the Growing from Seed forum here. The need to water depends on the soil mix you use, how well it retains moisture or not. Plus herbs, as opposed to most vegetables, have some unique germination requirements so the folks on the Herbs forum can be of more help with those requirements.

Dave

as digdirt2 mentioned herbs can be quite unique. That is why I buy some of my herbs like Thyme, Sage, and Oregano as plants. The only ones I try to start are cilantro, parsley and Basil. In my zone if its a mild winter my potted parsley will come back as a perrenial and if its a colder winter it doesn't I also have a pot of chives that I started from seeds once upon a time but they return like weeds no matter how harsh the winter If you think herbs are unique try house plants :P I bought all sorts of stuff once and the only thing I could get to grow was 1 China Doll and Id almost consider myself as an "expert" on seed starting but I prefer to use the term "intermediate" Difficult to be an expert when there are always new things to learn :)