If there is a wine or liquor store near you, or if grocery stores in your state can sell wine, this is a good source of boxes. The size of boxes that hold a case of wine is a good size for packing with books, as long as you don’t pack it completely full. Put the books in as if you were putting them on a shelf, in a single row. When you run out of room on that first row, that’s it. Yes, there’s space for more books in there, but don’t do it. If you put any more books in there, it will be too heavy to handle.
This is a good time to cull your spice rack. I’ve heard that you should pitch anything you can’t identify by smell, or anything older than 6 months. Also make sure you don’t pack any expired food from your pantry. It makes no sense to pack it up (or pay the movers to pack it), pay to move it, unpack it, then throw it out at your new place.
Jewelry, important papers, keys, garage door openers, credit and debit cards, driver’s licenses, passports, prescription medications, and anything you can’t replace (like the afghan your grandmother gave you for your wedding) travel with you, not in the moving van.
The “open first” box should include pet dishes and enough pet food for a few days.
Pets should not be wandering around free when the movers are working, even if the pets don’t have a problem with strangers. The pets can escape, or they could even be injured. A bathroom is a good place to keep pets while the movers are there, but do be sure there’s another bathroom that you and the movers can use. Also make sure you pack up everything in the pet bathroom before you shut the pets in there, other than the stuff the pets will need while they’re in there (food and water dishes, a litter box for cats, that sort of thing).
You can fly on some airlines with cats or small dogs in a carrier. The airline might need a certificate saying your pet has had its rabies shots if you do this. Talk to your vet a few weeks before the move.
Moving is very hard physical work. Be sure to drink lots of water while you’re doing it. It’s nice to have some bottled water on hand for the movers, too.