It can vary from ship to ship. Most can hold anywhere from 60 to 150. Those that have shore side tenders can hold up 250 and some larger. I know that the Norway has one of the biggest tenders. Lengths can very from 20 feet to 60 feet for a tender.
There is a large number of rafts for the crew. The lifeboats are meant for passengers. There is also a large amount of crew responsible for running those boats. All of them are motorized and are checked during the turn around time at a home port. If you get a chance get the book called "The QE2". It has a lot of good information about the industry. Also there are several good shows from The Learning Channel that explain the roles of Safety Officers and lifeboats.