I don't know if I have any great advice for getting started, since I feel like I'm kind in the same position as you (I love drama and teach at a school that doesn't have any kind of drama activities/club/classes/etc. really in place).
I've really wanted to get some activities started, but have always found it difficult to figure out where to start. I guess, this year I've been sort of shoved into giving it a shot though, as I've been "politely forced" into doing a twice a month drama club with a handful of middle schoolers (we are a K-8 school). I have been feeling my way through the process.
I've found a couple books that have been somewhat helpful . . .
Kids Take The Stage has been one of them. A computer CD program called the
The Drama Game File, I've also found good for finding great drama activities for kids of all ages.
Beyond that, again, I don't really have any particularly wonderful advice. I personally (even with my bit of experience) still feel like I have more questions than answers.
If there is anyone out there who has had experience in starting a drama club up, I'd love to hear from you too! Otherwise, I wish you luck -- If I can help you out in any way, let me know. Maybe we can even do some brainstorming off each other?