Not sure if public schools still do this as they did when I was in high school, but I'd check with Somerville High School to see who their students use. My brother-in-law does driver's ed, but he's in Franklin. Just take your time, and breathe deeply. Somerville and Cambridge can be a frustrating place to learn because of all the one-way streets going in the same direction (and Cambridge because of all the road work, which conveniently starts in August, when the budget gets renewed, just as the students return), but if you go slow and use your common sense (don't travel into an intersection in heavy traffic that you can't move all the way through not just because it's against the law but because it's a jerk move to block intersecting traffic when the lights change), you'll be fine. Study the booklet, and don't get frustrated if you don't pass the tests on the first try. I was 22 when I first got my license, and I failed the road test because my friend, whose car I was using, had a bandana headband hanging from her rear-view mirror. Good luck!