I have a friend who is interested in joining ,how does she go about this ?

I'm sure there's a "Sign In/Register" box somewhere near the top.

Why not send a PM to Oddie or one of the admin team (the ones with user names in bold in the members' list), supplying your friend's name and email address so that she can be pointed in the right direction.

Read the first post, a sticky, it suggests a pm.