Shanna Callaghan Cullen

First of all don't laugh at me if I'm not using the right terminology I'm trying to teach myself how to fix my truck. I have a 2007 GMC Sierra 2500 HD. And on my last short road trip I had a small fire under the hood, and ate away and decimated some wiring. I cannot seem to find anywhere online for free a picture of the engine and a diagram pointing at those wires so that I know where they go to. That way I can know what I have to replace. Thanks to anyone who can help or provide me with a website that I don't have to pay for anything right now because I'm not working.