Game Maker is a great way to start. It's a free game creation program for anyone of with or without a background in programming. Game maker has been recently replaced by Game Maker: Studio, but Game Maker 8.1 is still an excellent tool in making games. GM specializes in 2D games such as platformers, top-down games, puzzle games, and others. But there is a 3D portion of GM as well that is only usable in the paid GM Standard. I will not be covering this, or any portion of GM Standard.
So where do I get it?
The original versions of Game Maker have been discontinued, but you can still download Game Maker 8.1 for Windows and Mac here.