Well, I'd start with the FAQ's, which will be trememdously helpful. This'll get you there:
http://www.wdwinfo.com/dvc/faq.shtml
Another "non-official" Disney site brimming with info is:
http://www.mouseplanet.com/dtp/dvc/
It is, in a way, a "timeshare thing," but to compare it to the "old way" of timesharing, where you're locked into one property, one week, for eternity ... not at all.
You DO purchase a real estate interest in one of the seven Disney Vacation Club properties, and that's considered your "home resort." But you actually buy a set number of points, which are allocated to you each year. These points can be used in the year you receive them (your use year); you can also bank 'em into the next year, or borrow them from the upcoming year. You can choose four basic room configurations, from a studio to a 3 bedroom grand villa, depending on the property. And, you have the flexibility of choosing any time of the year to visit (understanding that certain seasons take more points.) You can also use your points at other Disney hotels, the
Disney Cruise Line, or 300+ resorts around the world (but frankly, that does NOT need to be the reason you buy into
DVC.)
Bottom line: if you plan on visiting Disney annually, and you stay in moderate or deluxe resorts, it's an excellent way to pre-pay vacations.
How much does it cost? Points bought from Disney, at Saratoga Springs, are $95 per point, with the possibility of some discounts. So, a 150 point contract would cost $14,250, not counting any programs to lower that a bit. Then there's resales which can be significantly less...
Gosh. Just keep reading.