My family just took the plunge as first time renters in mid-January for this coming December. Honestly, I had to do a lot of research to figure things out, because the rental agency websites are a little confusing, but here is the gist:
- DVC owners have points they don't want to use, so they offer them to an agent to "rent"
- Someone like us comes along, looking to rent points for a DVC resort at some time during the year
- We fill out the online forms with our requests for dates and DVC resort location, and the agency checks availability to see if there are actually rooms open (agencies usually charge for this, tho the company we used does not, which was nice)
- If there is availability, then with a deposit the agency goes forward and tries to match your points/date/location request with a DVC owner who is looking is looking to rent out their points
- If you match up with a DVC owner, the DVC owner takes your information and makes your reservation for you and your guests through their DVC portal (the reservation is in your name)
- The reservation shows up on your My Disney Experience page, and you can link tickets, ADRs and other things just like a normal reservation.
The big catch is getting in early enough to match your desired dates and location with a DVC owner before availability goes away. Many resorts have availability 7 months out, but the popular resorts and lower priced villas seem to go quickly, especially for particular weeks throughout the year. And then the agency still has to match you with a DVC owner with enough points to rent, which may be challenging if you're looking for a lot of nights at an expensive DVC resort, which may require a LOT of points.
Also, given that you're looking at going in September, a lot of villas (depending on location popularity and type of room) may already be sold out, or getting close to it. Studios and 2-brs tend to sell out first, followed by 1-brs according to what I've read. A previous thread did a nice job two years ago tracking DVC availability by resort from 11 months out all the way down to one month, which may help you visualize how likely what you want is available or not:
https://www.disboards.com/threads/p...-some-1-bedrooms-vgc-update-10-21-15.3419112/
My family rented for the first time in January for a December stay at BRV through an agency, putting our request in for a studio right at the 11-month mark, where the booking patterns showed our location as open to spotty for our dates in December 11 months out and completely gone by 9 months. Fortunately, it only took two weeks to match us with a DVC owner (tho the wait, not knowing what is going on behind the veil, can be a bit odd). If you believe those charts, we would have been completely out of luck if we waited until seven months out, so I'm glad we heeded their advice. We had absolutely no hiccups with My Disney Experience, and everything was effortless.