I am moving from an iBook G4 to a new MBP and don't know how to move my contacts from one computer to the other, so I can sync my iPhone again and not lose contacts.
The Address Book on a Mac includes an export option for the entire Address Book database.
At the Address Book menu bar, go to File > Export. With Leopard and Snow Leopard, the option is Address Book Archive. I believe this option is different with earlier OS X versions but the result will be the same. Transfer the export to the MBP. At the Address Book menu bar on the MBP, go to File > Import and navigate to the location where the export from the Address Book on the iBook is located and select it.
And my husband would also like to switch his iPhone over to this new MBP but doesn't want my contacts & I don't want his.
If you and your husband don't have separate computer login accounts - you both use the same computer login account and your contacts and his contacts are in the Address Book, you can make use of Address Book Groups - create an Address Book Group for your contacts and your husband creates a Group for his contacts. Under the Info tab for your iPhone sync preferences at Sync Contacts, choose Selected Groups followed by selecting the Group in the Address Book created for your contacts followed by a sync. Your husband will do the same under the Info tab for his iPhone sync preferences selecting the Group in the Address Book created for his contacts. Your contacts and your husband's contacts will be in the Address Book on the MBP, but only your contacts will be available on your iPhone and only his contacts will be available on his iPhone this way.
I used an external HD to transfer all iTunes music over, but all purchased music on my iPhone that I never transferred to my iBook is still on the phone, and I don't want to lose that.
After purchasing music with your iPhone, the music should be transferred to your iTunes library on your computer the first time you sync your iPhone with iTunes after doing so. If this didn't occur or you haven't synced your iPhone with iTunes on your iBook since this music was purchased on your iPhone, with your iPhone connected to iTunes on your MBP and without syncing, at the iTunes menu bar go to File and select Transfer Purchases From - the name of your iPhone.