Multi account with separate products management

[osit]

Hi,

I'm thinking about using PrestaShop for some bigger e-commerce portal. I have instaled few prestashop instances, played with configuration, modules, php and tpl files so I know prestashop a little.

I plan to create multiple accounts and assign products/categories to them but I still haven't found files that control accounts. If you know anything about that I would be grateful for sharing with those informations.