Various helpful websites:

Scratch

Scratch is a media rich programming environment developed by  Massachusetts Institute of Technology. It allows you to create and develop your own computer games and program them to do what you want. You can then share your creations on the web for the whole world to see and download - so a game you create could be played by other people all around the world! Creating games in Scratch introduces pupils to thinking logically and gives an excellent introduction to computer programming. It is free to download and there are versions available for Windows PC's and Macs.

Visual Studio