If USPSA strikes your fancy then Hopkinton Sportsmans will be running a 2 day Intro class Second weekend in March. I took the class last year and came away hooked, managed to shoot in a dozen matches since. It's short money considering you get two days of classroom and range time that covers everything from the all important safety rules to the best ways to approach certain courses of fire. We also run open practices on Weds nights starting around 5:30, all are welcome regardless of experience level and everything will be explained if you've never shot USPSA before.
I believe Harvard is running a similar class for IDPA coming up, there's a thread about it down in the Pistol Competition forum somewhere....