What the movers will not pack: live plants, pets, hazardous materials, paint, firearms, bleach, aerosol cans. Make other arrangements for these items. They also won’t unplug appliances or computers. That’s your job.
As for your computer, that’s another car item, if there’s room. You really don’t want it banging around in the back of a moving van, do you?
Ok, I’m sure you know this, but you really can’t pack your freezer and fridge items if you’re moving a long way. Throw it out or give it away. Canned goods should be fine. Just use your common sense. Candles will melt if it’s the middle of summer and they’re stuck in a moving van for four days. Cleaners can become hazardous material in the same conditions. You can re-buy these items when you get to your new digs.
If you’ve hired movers, it’s important that you be there when they are packing up your stuff. You don’t have to just stand around - you can help by cleaning up after them or continuing to pack if it’s not all done. Provide plenty of drinks for everyone (not beer, soft drinks and water will do!). They’ve worked hard!
When you arrive at your new abode, the movers will unpack all of your boxes and put together any furniture that they took apart (such as beds). They will not hook up any appliances. Also, they don’t care which room the boxes are supposed to go into. Most likely, they will just unload them all into one main room and leave the sorting to you. If you’re moving yourself, follow their lead. Just unload the truck as fast as possible and worry about sorting things into their proper rooms later.
You don’t have to help movers unload the truck. While they’re doing that, you can start sorting boxes into specific rooms (but stay out of their way). You can put on some nice music, offer drinks to everyone, even start unpacking or cleaning in places where they are not working.