That pretty much sums it up.

Yes, along with audio books (CDs and cassettes).  Hardbacks and paperbacks "cost" 1 credit, and audio books cost 2 credits. 

Check out the Help Docs at the Help Center.  Here is a very important link to the book condition guidelines:

http://www.paperbackswap.com/help/help_index.php

Thank you.  I looked but couldn't seem to find the answer. Thanks for the link.

I hope so!  That is about all I send out!

Welcome to PBS, Jessica.  In the Help Center, under "What Can Be Swapped Here", it states:

Allowed:

• Paperback books
• Hardcover books (dust jackets not required)
• Audio books (must be originals, not burned copies)
• Ex-library books
• Books with accompanying media
• Textbooks/Workbooks 
• Foreign-language books (if in a language other than English, the language must be specified in the book description)

Not allowed:

• Anything that is not a book
• Anything that contains advertising
• Advance Reader Copies (also known as ARC s, Review Copies or Uncorrected Proofs--these are not the final versions of books)
• CD-ROM books/e-books (books that must be read on a computer)
• Burned copies of audio books
• Xerox or otherwise unoriginal copies of books
• Unbound pages
• leaflets or pamphlets or booklets* without ISBNs (other members complain at spending a credit for these)
• Books that require supplementary non-media materials (non-media materials cannot be sent by MediaMail)
• Pornography (sex manuals and erotica are allowed, hardcore pornography is not allowed)

Cheers,

Catt