This website explains how to set up everything in a Portal 2 game that you create, so if you miss any class by pull outs or something else, like myself- you could try so learn it on here
For those enjoyed learning code... I know I did, here's another game based learning website that teaches you how to code in javascript and HTML5 and CSS3- if you wanted to learn... C:
Hey, these tutorials are really good for all minecrafters trying to learn how to use redstone. It has a total 25 videos and it also teaches some of the basics to using redstone....
This site is pretty useful for those looking for the more animated cartoon style characters, though it doesn't have many it still may prove useful to some people