Howto create 2 user groups with different access based on register?

I would like to have 2 profile type on register:

1. One with free register and access to the public part
2. One closed group and access to the open part of my social network and access to some hidden groups

If a member one to be a part of the closed social network I need to approve the member.

Is there a plugin that fit my needs? Or do I need to code it manually?

I did try to installe "profile manager" - but the type thing doesnt seems to work...

Any help or any tutorials I need to read?