How Do I Edit Pics?

Lol bit of a noob question but I want to sell my rs acc on sythe but need pics. Can someone explain... I know you print screen then you paste into paint... but everytime I do that the pic goes REALLY small on sites and you can barely see it... NEED HELP!

 

Download yourself A screenshot taker, paste into paint or p.s.p, blur out the names whack it up on imageshack, don't click the resize button, and there you have it.