I'm New Need Help Understand Codes

Hi all, I just found out bout this great site and just signup. I see lots of info knowledgable people here sharing hack codes but I knew nothing about. I want learn how to use these codes are there any sites or forum here teaching newbie like myself how to understand them and put them to use. Greatly appreciated thanks. I play MW3 and BF3 alot and and like to do hacks myself instead of buying monthly subscription from others.