The best way to book depends on your comfort level. I book all my own stuff whether it's Disney or anything else. BUT, my DM took us on vacation every year while I was growing up to many places. Then she & I took many cruises while I was a young adult. So I have extensively travelled & even taken
travel agent classes (but I am not an agent) and therefore very comfortable taking care of all the details.
Also I am a DVC owner and actually rented quite a few points to others earlier this year but before I did so, I read EVERYTHING that was available about the subject in the DVC Rental primer section and other stuff that the Moderators recommended. Almost all of the time, it is a great way to save money and stay in the Deluxe resorts. Just remember, if anything about the process makes you uncomfortable or just doesn't seem right, DON'T go through with it. Pick another person to rent from.
When I was renting my points, I kept up with my thread. I answered people in the order that they contacted me and I checked on the ressie requests in a very timely manner. I also offered a written contract up front and followed through on everything that I said I would do. I also talked on the phone with my renters and answered their questions so that they would be comfortable and get that I would stand behind my word.
So far, my first renter has had enjoyable vacation, they even made me a card after with some of their pics. They look like they had so much fun! My second renter will actually be there shortly and we will cross some of the time. We are trying to plan to meet in person--our kids are similar in ages.
Good Luck!