In need for tips in social networking

Hello everybody this is my first post and i don' really know what i'm doing, so i'll go right to the point.

I'm thinking of buying dolphin and ray unlimited license to start my own Social Community Network,
and i was wondering if any of you can share tips on how to start, and by this i mean like:

• Of legal things i most know
• On how to incentive the user generated content
• What i should and should not do
• etc.

And all the things you people can think about that i should know before starting my SCN.

Thanks in advance.