Multiuser Blog Network

Hi everybody,

I want to establish multiuser blog network as a theme of woman in a local project but I’m an amateur WordPress user. I just wonder to use/convert WordPress multisite and buddypress like http://www.blogher.com .
I bought a theme name is Powermag which is very close to blogher. But I don’t figure out how to solve below:

1. User will register to my site.
2. She will click the “add post” buton on homepage and text editor will be opened on website (not wordpress panel).
3. User have her own blog.

I added post in page plugin but I don’t understand how I connect this function with front page.
I want to work/hire with a freelancer but first I have to know to establish these feature works properly.
I’m glad to help me.

Thanks a lot.