We have always been relocated with the company, who tend to sort out the logistics of the move.
However there are a few things to help things along.
Passports, are they up to date?
Copies of important documents, wedding cert, birth cert etc.
Injections, medical notes, medications and repeat prescription. Are you upto date on smears etc? (Finding a doctor the 'other end' might take some time)
Do some reaserch to the area in which you would like to move. It can get confusing just to turn up and get the real estate people so show you a few places. Narrow it don't before hand.
Get a job. I wouldn't relocate without securing a job before hand. Just too risky in my opinion.
Check out schools, services etc.
Install Skype on your computer!
Good luck