how to unblock a person inmy email address book?

first of all, it would help to know what you are using as your email.

If it is Outlook...........
select from the top Options -> Junk emails -> Junk Email Options
there should be some tabs there. If you blocked them, they will be in the 'Blocked list'. Just select the email and press remove button.
If you trust them, you can add them into the 'Trusted List'.

hope that works.

anya
October 2008