Good question. I don't think there is a one-fits-all answer but I can share some tips from my own experience.
1. Have fun and enjoy the move. Your mood may spill over to the rest of the family. It is a big task to do but worth the investment.
2. Involve your kids as much as possible in little errands, packing and unpacking their stuff, planning the new place etc. Make it a positive experienced for them.
3. Say good bye to the old place and friends you may be leaving behind, same for your kids. There are many ways to do this, and you will certainly have your own way of doing it.
4. Encourage your kids to stay in touch with good friends, this is relatively easy with internet and skype.
5. For the practical stuff: get rid of everything you no longer need and have not used the last couple of years. Give away to friends, charity or sell.
6. Ask your friends for help, don't make it a lonely chore!
7. Help your kids make new friends in the neighbourhood and at school.
Hope some of this helps :-)