You can find a bunch of stuff about modding games online--along with a bunch of scams and malware as well.
Basically, modding games involves altering files the game uses; with consoles, the extra step is added in that you have to make sure you've taken the necessary steps for your console that allows it to play burned games.
Just try to Google around for starters; you're more likely to get help if you have a specific issue, rather than asking a question that might take fifty pages to adequately cover.
Then again, it might just be easier to stick with PC games and go from there. Personally, never got into modding games beyond that of plain-text config files. The payout just wasn't worth it to me.
"I'm going to get into your sister. I'm going to get my hands on your daughter."