Normally you would send an email or PM with your nominated email address to one of the admins so that you get notifications of primes found and also so they can talk to you about any work in progress aside from the posts in the project forum.
(see the forum link under Community in the project site menu)
Then you would post in the "TEAMS: Join a team" thread
http://www.mersenneforum.org/showthread.php?t=10826
However, I can take care of both of those for you.
I have a "user registration" page on the to-do list.
I posted instructions on our forum somewhere about LLR configuration.
I'll dig it up an post back here soon.
(I really should put that on the project site too, duh!)