There are two kinds of introductory sections: those you wrote and those someone else wrote.

Guidelines

• Include the introductory material you wrote (aside from the list of names you thank for writing the book).
• Leave out most introductions to the printed book by written by others. Certainly leave them out if they are nothing more than hype or praise of your abilities as a writer. But if the person who wrote it is famous, you might want to let the listener know.
• Dedications (for the printed book) are usually short, and can be recorded if you want to.
• If you want to dedicate the audiobook to someone, record it.