Root [noob] stock 2.2.1 rooting question

Ok, when I read the guides to rooting your 2.2.1 optimus m they mention a stock 2.2.1. Does this mean that I must not have installed any other programs? cause I'm about to root my phone and I was wondering if the programs that I have installed are going to cause a problem. should I uninstall them? and how could I save my saves for gurk and angrybirds, seasons, rio.

thanks in advance for your help