This is the exactly right place, Skyre.
First of all, may i direct you to something my friend Moraline came up with, admittedly with a lot of suggestions from other people, but it was her idea....http://elliquiy.com/forums/index.php?topic=164265.0
That thread gives you a long list of hings that you may wish to include in your recruitment thread.
The next thing is to get down to brass tacks. Do you want o run the game as system or freeform?
The advantages of system games are many and there are others here better qualified to give them, as I've never run a true system game, nor participated in one. However, as I see it, a system is required if you expect to have a large amount of Player v Player or Player v Environment combat, in which player characters can get killed off.
If your intent is for the game to be mostly smutt based or story based with PCs only dying if the player drops out, or a sandbox with the same criterion, then freeform is probably the way to go. It is still possible to have PvP in a freeform game, but it takes a little more planning and maturity on the part of the players!
I would suggest creating an interest check thread first. Detail your idea, and the characters - or types of characters - you require, give a broad outline of the story if there is one, and take it from there. Always reserve yourself a couple of posts at the start of the thread to add detail to later.
If no one else is interested, then you've not wasted a vast amount of time. If you get enough interest, come back here and ask us what to do next!
Actually, the next step is usually to create a blank character sheet for interested players to fill in, but most of us will add that when we know we have people interested.
If you are unsure whether to do system or freeform, you could ask that question in the recruitment/interest thread once people are interested, or even in the initial post itself.
One thing I would suggest for your inerest check thread: Make it colourful. Put a nice big colourful picture at the top, under a bold, colourful heading. It grabs people's interest beter than a wall of text.