After the discussion on the Forum User Groups thread, here are the instructions on joining a group and setting your title.
Request Access to a Group
1) Go to the Groups page.
2) Click the “Request Button” under the group:
3) Answer any questions that popup and then await approval 
Change your Title
1) To change your title, go to your profile settings.
2) Scroll down to your “Title” settings and choose your title: