I got 1 credit given to me (that is all they had) and I through PM made the deal to send 2 books. Now how I can make -print a label using the PBS money ? OR should I just hand write and put stamps on pkg.

You can post the book to your bookshelf and then click on the title.  It will have a link for "Mail to a friend."  Click on it and it will let you type in the address.  You can then proceed as you normally would when mailing out a book.  Just make sure that you change the weight to reflect the weight of the package that you are mailing. 

This will not work if the books are wishlisted though.  If the books are wishlisted that you are sending, you can just use another title to create the "mail to a friend" label.   I hope this helps.

You can use the same label for both books - assuming you want to mail them together.  Just adjust the weight on the label page to reflect the higher weight.  If they're both PB's you can wrap them together by using an extra sheet of paper.