You can also check the boat links on this site:
http://www.winnipesaukee.com/links/Boating/
Anchor has power boats for $1200 a week and up. You may also need to take a boater education exam. Depending when you where born, etc. See here:
http://www.boat-ed.com/nh/course/p4-3_whomayoperate.htm
Finally get a chart from this website it's less than $20. Winnipesaukee is huge, rocky and easy to get confused on.