You have two options - you can call Disney and just book a villa at the regular price using dollars, just like you would any other hotel room or suite (but keep in mind that the villas are very pricey doing it this way). IMO, the best option to get the most bang for your buck is to rent points from a DVC member for your stay. Go to the DVC message board on this site, and then the "rent/trade" board, which has Frequently Asked Questions (FAQ) about the point rental process. Basically how it works is that you figure out when you want to go and what size villa you need and where, and then you can go to the DVC point calculator (follow the link from the message board) and put in your dates and calculate how many points you need (for example, you might need 200 points to rent a 2 bedroom villa for 5 or 6 nights).... then you post a message on the board saying something like "200 points needed for a 2 bedroom villa at Beach Club in January 2004" and then wait until someone responds.... also look through the messages of people looking to rent their points - if they have available the number of points that you need, email them. The general going rate for points is $10 per point (so 200 points would be the equivalent of $2000). There is no tax on point rental. Once you agree with someone to rent their points, ask that they make a reservation for your desired dates in YOUR NAME. Usually you will send them a deposit right away ($100 is standard) and in return they will send you the written confirmation of your reservation. Then you agree with the person when you are going to pay the balance in full (usually 30-45 days before your stay, but you can make whatever arrangments are agreeable to both parties). Point rental is a private transaction that involves trust on both sides. I have done this 3 times now and had terrific experiences and great values. I highly recommend point rental.
***A word of caution, the points necessary to rent a DVC villa DOUBLE for Friday and Saturday nights.... if you want to rent points, your best way to get a good value is to plan to arrive on a Sunday and stay until Friday.... Try to minimize the number of friday and saturday nights in your stay, because it is literally double. If you want more nights than just sunday through Friday, I would recommend splitting your stay so you don't pay a huge markup. Stay Sunday through thursday nights at the villa, and then reserve a room somewhere else for the weekend nights.