From MozillaZine Knowledge Base

When trying to print an Address Book, currently it will print out in the order the addresses are entered into it. AKA Bug 118900 Please see the bug and vote on it if you want it fixed or addressed.

Work around (for now anyways)

1. Create a new temporary address book.

2. Select all cards in original address book. Select "View -> Show Name As -> Last, First."

3. Drag all cards to new address book.

4. Cards in new address book will be in order.

5. Delete all entries in original address book.

6. Drag all cards from temporary address book to original address book.

7. Delete temporary address book.