We have owned 2 timeshares ourselves. We sold one last year and will be attempting to sell the other one this year. Where you can sell it will depend largely on how much you want back out of it. The 2 we purchased, we got off ebay and payed almost nothing for. One was $250, the other was $1250 (+ ~$400 closing costs on each). The use we got out of them for several years was definitely worth it. The one we owned in Daytona Beach we sold through a real estate company that worked with that resort. You may want to contact the place you own through and see if they work with or recommend a place locally. We had to pay a commission, but it was well worth it in the end. It was done like a typical real estate commission. Nothing paid up front, only paid if it sold and taken out of the proceeds. Everything was completed and check was in hand within just a few months.
Our other timeshare is in Hilton Head and, unfortunately, is in a resort that doesn't partner with a local real estate company. I have looked at several sites that you can list on for free (
Timeshare Rentals Resales Timeshares for Sale Rent Vacation Condos) or for a relatively low fee (
Timeshare Rentals, Timeshare Resales, Timeshare Ratings, and Timeshare Reviews) that seem to get a fair amount of traffic. Hopefully we will get ours listed in the next couple of months, as the vacation season starts to pick up. There are many other sites out there, as well. Definitely stay away from the "pay us hundreds up front & we'll sell it for you kind of deals". Also beware the ones that say they have a buyer just waiting for your timeshare.
Good luck selling your timeshare. I hear this is going to be a tough time for it, as they are definitely luxury items.