First, I recommend going to the
DVC boards here on the DIS. There, you will find a board titled "DVC Rent/Trade" or something very similar. On that board, there is a sticky to read that gives many details about renting points. I am renting points for the first time for my October trip & this is what I did.
First, I decided when I was going, which DVC resort I wanted, and what villa size I needed. Then, I looked at the DVC
point charts to determine how many points I needed for my trip. I have a book, because I'd gotten info on the DVC, but there are also point charts on
www.allearsnet.com and maybe here on
www.wdwinfo.com. After knowing what I needed, I posted my desired point rental, dates, and resort on the Rent/Trade board. Of the several responses I got, I evaluated each by seeing how long the member had been on these boards & I read several of their other posts, to get a "feel" for their personality. I made my choice and contacted her regarding details. FYI, I am paying $11/point. I did not make a price demand in my post; I just made that part of my evaluation process of the responses I received.
From here, each DVC member is different in how they handle rentals. Some require full payment up front. The person I'm renting from required 1/2 down & 1/2 45 days before arrival. It's non-refundable. The person I'm renting from does give me the option of rescheduling within a certain time period if I have an emergency. Some are not that flexible. Renting points certainly takes trust, on both sides. Your reservation will be in your name, but you cannot change/cancel it yourself. The DVC member retains control of your reservation. That's why it's important to research the person you're renting from. Some people do not like that aspect of renting points. Personally, I don't think it's any different from renting a condo on the beach from an individual, and I've done that many times.
I hope this answers your questions. If you have more, feel free to ask!