Technical Details about reselling

Im planning to do reselling with my Crazy Insane plan.
Im just planning to have 4 clients at most but can anyone please tell me how to set up those new accounts? Should I use Fully hosted option for every new site or should i remap directories and what about users should I create groups, Im just trying to find the best way so all my clients can have their own site secured without interferieng with anyone else.
and last but not least what about payment options how do I charge my clients?
Please any advice would be greatly appreciated.

What level of access do you want them to have?

Im not really sure I would love to see how anyone who resells hosting do it.
From the top of my head Id say
FTP access which is not a problem.
Creating Databases limited amount
Creating email accounts limited amount
It would be great if they could have their own control panel I dont think that would be possible... but anyway Im wide open to hear suggestion on how to handle a max of 5 to 10 clients.
I know there are going to be limitations... im in the learning process .....

Thanks