It sounds like you probably know what you are doing by now, but I do have
this guide on making money with this hobby that you might get some use out of. What you have on hand is entirely dependant on what kind of detailing you plan on doing. My original stock was just a simple paint cleaner, a wax, some interior products, engine degreaser, lots of armor all, and some glass cleaner. As I ran into more complex problems or read about better products my supply quickly outgrew my trunk.
I would definitely not charge people money if you are going to be using the Mr. Clean crap. If they see you using something to wash their car that they can pick up at any WalMart and then you charge them $40 bucks for your trouble, then they aren't going to be giving you any referals. There isn't anything that thing will do that you can't do better by hand. It was designed for the lazy person who just wants to wash their car and not spend any time doing a good job at it. Just stick to bucket washing and using a good drying towel. That will make a much better impression than using half baked techniques and products that they could do themselves.