In the words of Kevin Hart: "We gon' learn today!"

So my Jeep won't start.

The other day I swung by Valvoline instant oil change just to get air in my tires. When I start it back up it cranks real slow. It sounded very "bogged down," and they all laughed at me and said it sounded like it was about time for a new battery. I have been told for years by other people that it sounds bogged down whenever I start it, but this time even I noticed the difference. I drove it around town the rest of the day Friday and it started fine a few times.

Sunday evening: Jeep won't start at all. No cranking. But the radio and guages turn on. This happened to me a while ago and it was just corroded battery terminals. So that's my first idea. BTW the battery was purchased in January 2008, the week I bought the TJ.

Today I cleaned the terminals and took the battery to the parts store. They charged it and said it is functioning just fine. I bought a new clamp for the negative side because it looked pretty rusty. I replaced it and tried to test start the jeep before installing things like winch, etc. Now it was turning over quite happily, but STILL not starting. So what's next? I was running out of time so I decided to just attach the winch, etc and secure everything and come back to it later. While tightening everything down the brand new made-in-China-clamp crumbled in half. When it rains it pours.

I guess I've never been through a full troubleshooting process of a vehicle that won't start. What is the proper order and method of things to test? Any help is appreciated!