There are game development communities on http://www.gamedev.net/ and http://www.indiegamer.com/
However nobody will react well to some random person just barging in with an idea, and it is crucial that you understand why. The first article on Sloperama addresses this issue:
Although his advice talks about selling the idea, getting others to make it for you amounts to the same thing. Basically, you are going to have to build it yourself because noone else will do it for you. That doesn't mean you have to do every bit personally (ie. do all the programming, create all the art, compose all the music, etc.) but it does mean you have to work hard on it.
In order to get anyone else interested in your idea you have to be coming to the table with a lot. It helps a lot to have developed games in the past, so I might recommend setting your great idea aside temporarily and go develop a few small games (Tetris, Pacman, that sort of thing) on your own to develop rep.
ADDITION: Your use of the term "baby" in describing your idea is a red flag. That may mean you are too in love with your idea and expect other people to just do what you tell them. I hope this isn't the case, because you have to realize that unless you are hiring/paying them (up-front cash, not a promise of future profits) then this venture is just as speculative for them as for you and they'll rightly expect to have a lot of creative control too. Basically you should look at it like "hey does anyone else want to work with me on a shooter?" and then the details are worked out in collaboration with them.