There is a good step by step guide on reddit under the ethermining sub reddit that has everything you need. There are some decent youtube clips that can also set you up pretty quickly.

Like some people have already said, you'd probably be better off protecting your computer from damage instead of mining on it. You can go to a website like whattomine to see what kind of value you'd be getting.

Also, if your video card is only 2gb, you can't mine ethereum.