Check out this link...it should help explain a little more. Through this link you will also be able to check out the different DVC resorts etc. (use the Destinations link). They recently announced Bay Lake Towers (BLT) at the Contemporary as the newest DVC resort. It is only for sale to current DVC members RIGHT NOW and the sales will open to the general public next week.
http://dvc.disney.go.com/dvc/guest/about/guestAbout?id=ProspectsHowMembershipWorksPage
DVC is a flexible timeshare system where you purchase points at a "home" Disney resort. You have a priority booking window at your "home" resort of 11 months and then can book at the other DVC resorts at 7 months. To help you figure out how many points you would need you study the
point charts for the resorts and consider the size unit you would probably want to stay in most often (the accomodations vary slightly from resort to resort but basically they offer studios that sleep 4, 1 bedroom villas that sleep either 4 or 5, 2 bedroom villas that sleep 8-9 and Grand Villas that sleep 12). They have 5 seasons, so you then decide which season you would most likely travel in and then find the corresponding number of points. You can bank and borrow your points too - so there are a lot of people who own DVC who do
not go every year. They purchase enough points to bank and borrow for the size unit / season they want and they go once every 3 years. We purchased enough points at SSR to be able to go for 2 full weeks during the peak summer season in a studio if we wanted or for 1 week in a one bedroom (yes, the points can vary by that much) OR we could take others with us and spring for 2 studios for one week. To be more frugal tho, we could travel in mid-August when the points drop and only go for 5 nights (weekends use more points) and we could get a 2 bedroom unit. It is not like a traditional timeshare. You are not locked into a specific time of year or unit size. It's very flexible.
The units are considered "deluxe" accomodations and there are a few small perks to being a member - one is $100 off Annual Passes - so if you DO go every year or for more than 1 trip a year those are a real deal.
There are links at the top of the DVC boards to the point charts and for resells (purchases made not directly thru Disney). There are annual maintenance dues (per point purchased) and they vary from resort to resort. I think the Timeshare store has a link to the maintenance fee charts.