Hello. :)
Well, hopefully the first post in the thread covers it all... basically anyone who who wants to be a Beta Reader - a person who looks over one's story before they post it and offers advice on what to improve, mistakes, etc - can apply and be added to the list of Beta Readers available. Then someone who needs one can simply look at the list and contact anyone who they think will help them best for their story.
Alternatively, if one still isn't sure who they want as a Beta Reader or can't find a free one, they post in the thread using the outline provided giving infomation on what kind of Beta Reader they need, their story, etc. Then I update their details into the first post so others can see.
Basically a system to help others find a Beta Reader for their work, and particularly good for 'newbies' to improve, although they are good and helpful for everyone. (I used one myself for my most recent story, for instance).
Hope that answers it, any other questions just shoot away. :)