It's been asked, and answered, a few times:
One recommendation: try the site search, be specific, as with over 1.3 million answers and more than 200K questions...much ground has been covered already :)
You have to have a certain number of points to use the site, everybody starts with the same number. Certain features (fun mail) only unlock after so many points earned.
i noticed when i first sign in it said i had 25 points ..what does that mean ?