Okay, first some bare basics. There are two ways to buy into DVC. One is by buying direct from DVC; the other is resale. I highly recommend either option. I initially took the tour at SSR and got the basic information from my DVC guide, bought resale from TTS, and just today bought an SSR add-on direct from DVC. They were both wonderful.
All points are not created equal. Saratoga Springs contracts expire in 2054; all of the other resorts expire in 2042. There are no cookie-cutter solutions, so you have to research thoroughly and figure out which best meets your needs. A thread which will hopefully help you is
http://www.disboards.com/showthread.php?t=778634
Direct: If you buy direct from Disney, you will pay $95 per point at Saratoga Springs, or $89 per point elsewhere. The price at Saratoga Springs goes up to $98 either 6/5 or 6/19, depending on which DVC mailing you believe. Actually, I think the price for existing owners is the one that goes up later, but I'm not sure of that. At Saratoga Springs currently, there is an $8 incentive, which means you really pay $87 per point. Confused yet? We haven't started.
If you buy one of the "sold out" resorts (Old Key West, Beach Club, Boardwalk, Wilderness, Hilton Head, or Vero Beach) direct from Disney, you pay $89 per point and the sale is obviously subject to availability of points. Generally, there is no problem getting points anywhere but Beach Club, and then only in certain use years.
Resale: You can also buy any of the resorts resale. Generally you will find that the resale prices are lower -- sometimes dramatically lower, depending on resort. With resale you may be expected to pay closing costs (negotiable, like everything else), buying direct DVC pays the closing. Regardless of how you buy, once you are in, there is absolutely no difference between points bought resale and points bought direct. (In fact, I don't think there is any way of anyone knowing where you bought your points.)
There are several realtors who specialize in resales of DVC timeshares. Fortunately, one of them is The Timeshare Store (lovingly known here as TTS), which as luck would have it, also happens to be the sponsor of this forum. You can click on Current DVC Resales at the top of this page for TTS' current inventory of resales.
Check the thread above, do a bunch of research, and never be afraid to ask a dumb question. Your dumb questions are the very same dumb questions we all didn't know the answers to when we started.