WPMU + ProSite + BuddyPress + Membership

Hi

I've very Confused.

I'm trying to build a website like wordpress.com or edublog

i've installed all what i need
and need to start to show up

confused int he registrations as i need to use WPMU with the Buddypress and the PRO SITES + MemberSHip + Affiliate

as i'm offering many kinds of websites

now i'm confused with the registration process for the Clients ...
how will it go and how is the integration between all of these plugins?

i'm offering normal free blogging network With Pro Sites