Please suggest me some plugins in WordPress networking

Hey guys i’m creating a site network using WordPress. Lets say my site name is blahblah.com
and lets say i have 10 subdomains like site1.blahblah.com,site2.blahblah.com

Now i want something like this. There will be no articles in my main domain. But i want list all subdomain’s articles in my main domain. When they click read more button users have to redirected to original article.

I also want multisite access facility with single registration. That is if a user signed up in my main domain, then he should able to access all my sub domain using the same login credentials.
Some says use the same database for all domains. But i dont think thats a good idea.
Is there any premium or free plugin available for this feature?.
Thanks.

Solutions Collecting From Web of "Please suggest me some plugins in WordPress networking"

There are two plugins that do exactly what you want, and I have used them both extensively.

First, ThreeWP-Broadcast. This plugin lets you “broadcast” posts from your sub blogs to your main blog (or the other way around). It also allows you to link to broadcasted post to the original, as well as auto create tags, categories, custom fields, and featured images.

Second, is Multi-Site User Management. This is a little plugin that you drop in your mu-plugins folder and it will keep your users synchronized across all sites, allowing them to login into all the sites with the same name.