I have been development my game for a while and I want to announce it to the world, but I am not sure what needs to be in the press kits I send out.

I hope this is in the correct area. I am trying to game into the business of being a game developer. However, if it is in the wrong area please tell me.
Thank you.

Try reading some press releases. That's what I would do. And also in the press kit you put tchochkes - stuff with your company logo, your game title, on it.