I teach tennis lessons, to players of all skill and experience levels, at MIT in Cambridge, MA (more detailed map with parking information here). Lessons are outside in the warm months, and indoors from October to May. All lessons are booked inside during the winter. A great place to start is to do this self-evaluation to help you understand what you'd like to improve. Be sure to include your contact info.
My approach is to start by helping every player understand their own game from an outsider's perspective. We talk about how what their strengths and weaknesses are, and then begin thinking about how to become stronger in the short- and long-terms. This can range from understanding rules and basic stroke production to high-level tactics and strategies. For competitive players, I also emphasize mental skills for competition.
Most players will investigate: the different kinds of spin, the reasons for their use, and how to make them happen; technical and efficient stroke production from the baseline; principals and techniques for good net play (and how best to counter net players); good technique for both first and second serves.
Private lessons are $70/hr, including court rental at MIT.
For two people: $86/hr.
For a pre-paid package of five lessons, subtract $5 per lesson. Ten lesson packages, subtract $10 per lesson.
Please ask about larger classes. Lessons start on the hour.