Click on the link above your post, "brining 101" and it should answer most questions. If not, please go to the "open forum" and ask and we'll try to help you out.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .