In case you forgot how (or you're just looking for a refresher course):

How To French Kiss

Some good pointers:

4. Start off with a normal kiss, not too firm, not too aggressive. Closing your eyes is optional.
8. If they open their mouth more or otherwise indicate they like the kiss, keep on doing what you have been only with a little more passion.
9. As the kissing gets going saliva build up can be a problem, don't forget to swallow.

Gosh, I wish tutorials had been out there when I was, um, younger, and had not a clue what to do the first time some guy came at me with a kiss in mind. Oh well, you live and you learn.

Via Elaine