What db tables does contain information about the blogs …?

Hi, would like to make use of this plugin “Site Categories” – using it with wpmu and buddypress installation. In order to use pics (img) for the (sole/ single) sites – an other plugin, “avatar img …” is neccessarry – but this plugin does not work with buddy press. But I am using Buddy Press. Not sure if I am able to modify the plugin code (non techie guy!), but what are the database tables name I would have to look for the relevant information… like categories, blog names, etc.? Could´nt find this in the php file…!