Hello Friend,
1) The only free & paid model of an on-line game I know is SecondLife. Your first step will be to logon to it and play it a while. Make notes on what you like and don't like. Study what you can about their business. Read every article you can find about them in business and technology magazines.
2) You are not going to do something like this for free. Many of the technologies you can use for free and that will help. All RPG that anyone would pay for are 3d graphical (gone are the days of MUDs) so you are going to need a client server model and a 3d engine. See below for a link that has a decent list of them (but I bet you could find a better list pretty easy)
3) Role playing games are popular. I guess I did it the old fashion way with Dungeons and Dragons with books, maps, papers, dice, math and reading and writing. But RPG appeals to many because you can socialize, go on quests and solve puzzles together or just hit things and watch them die.
4) In terms of resources, you are going to get them from your local job pool...or maybe not. In the book, "The Wolrd is Flat" the author points out that you are not limited by geography anymore especially for this kind of stuff. Popular and well done programs like GNU/Linux, Apache and such have proven that. To get money or people, you are going to need money. After you study up on this stuff, you will be able to make a list of skills you need. After you have a sound business model, you can get financial backing (ok, it is a little harder than it was a few years ago).
You may have a long road ahead of you but this is possible. The company Id (Wolfenstein, Doom, etc.) started as a few people in a garage.