Uh... good luck with that...
EDIT: OK, I'll elaborate. You've told us basically nothing, shown us nothing and your joining date doesn't exactly fill me with enthusiasm about this game. Unless you know what you're doing- I mean REALLY know what you're doing- then I suggest you start small. Learn the fundamentals of FPS game design and level design. One day, you can resurrect this idea to it's full potential. (Although I hate to burst your bubble, but a CSI game in FPSC would be extremely limited, if not impossible. Especially for a newcomer.) Also, watch your spelling and grammar. We have nothing else to do, so we ridicule people's spelling to pass the time. The last guy was hung, drawn and quartered.
If it feels good, it's a sin.