I tried doing a search on here with little luck, but I'm not the best at searching forums so I apologize if this has been asked a million times. We recently bought an RV with lots of help from this...
If you're interested in this type of camping, check out Thousand Trails, they're one of the better known types of membership campgrounds. Not our cup of tea but you can frequently fine memberships for sale on the secondary market for a fraction of the original cost. Though I've read good and bad about them here they are one of the better established companies.