IPhone and Address Book sync

Question

My address book has now got some contacts.
1. how do I format it? (how do I delete all contacts at once, just to clean it up)
2. after the clean up, how do I sync my iPhone contacts with address book? (I need to send all my contacts that I've got now on my iPhone to my Mac's address book)
3. how do I sync address book contacts back to the iPhone (if I buy another iPhone, how do I transfer all those old contacts from the address book to the new iPhone?)
thanks

Answer 1

1. how do I format it? (how do I delete all contacts at once, just to clean it up)
You want to delete all contacts in the Address Book on your Mac?
If so with the All Contacts Group selected, select a contact in the All Contacts Group. At the Address Book menu bar go to Edit > Select All. Follow this by going to Edit and select Delete Cards. This will not delete any Address Book Groups you created, which can be deleted separately. Any Groups you created will be empty after deleting all contacts from the Address Book.
2. after the clean up, how do I sync my iPhone contacts with address book? (I need to send all my contacts that I've got now on my iPhone to my Mac's address book)
Enter one contact in the Address Book on your Mac. Make this contact up if needed, which can be deleted later. This will provide a merge prompt with the first sync for this data, which you want to select. Syncing contacts with the Address Book on your Mac is selected under the Info tab for your iPhone sync preferences with iTunes.
3. how do I sync address book contacts back to the iPhone (if I buy another iPhone, how do I transfer all those old contacts from the address book to the new iPhone?)
Select Sync Contacts under the Info tab for the new iPhone's sync preferences with iTunes followed by a sync.