Metal Gear Solid, I have never played any. Explain plot and characters please?

I have been liveing under a rock for a long time. I have never had any interest in the games. I now have nothing to play till Final Fantasy XIII comes out. Can you tell me what the game is about, and who is who. Can I start with 4, or do I need to start with 1. How are the storys related. All I know is someone is called Snake, but that's it. I think it's the old guy with the eye patch. Then there is another old cowboy looking guy. And a younger guy that looks like Charlie Sheen. I thought that was Snake, but what do I know. I like RPGs and VS. fightting games. The first Doom and Doom 2, and Quake III are the games I like to play. I don't like games like Rainbow 6, and Resistance Fall of Man got old fast. So would this be a game I would like. Thanks for any info you can give me.