I have been researching the same thing!
I spent a while last night surfing tinternet, found some useful vids on youtube, just type in the product or mequiars etc.
Detailworld is a good place to start, and also the mequiars website/uk forums.
I agree with NFS totally though, when you price up the cost of the machine, polish and pads, its not far off the cost of a detail. I now know how to look after the car after some self educating, its just the initial prep and paintwork correction I need.
But, probably like you I enjoy cleaning/detailing, and the investment of a good machine and accessories will last you for along time and many happy hours having fun. (if you like that sort of thing of course
)
BTW, the meguiars 3 stage sytem appears a better choice for correction rather than the AG range, but then i've only been looking into this recently too? Probably a lot more better things out there?
Good luck!