Here are some helpful tips that can reduce the stress.
Research where you are moving to see the type of culture, climate, customs, currency and other important information. If possible visit the country before you make up your mind, don't rely on other people's impressions. Ask yourself if the new culture will really suit you (and your family).
Murphy's law: If it can go wrong - it will. Don't assume that you'll be able to find the perfect job or house immediately. If possible make sure you've got enough money to see you through the first couple of months at the very least (preferably longer). Start preparing as early as possible, just getting all the necessary paperwork in order can take a long time.
Make a checklist of everything you need to do!
Good budgeting could be what makes the difference between a successful relocation and a disaster. Before you go, work out what everything is going to cost during those crucial first months when you're trying to find your feet in a foreign land.
If your company has initiated your move, you may be eligible for relocation benefits.
Make sure that the country you are moving to has adequate healthcare facilities and infrastructure to support you (and your family), especially if you suffer from a medical condition which requires treatment or medication.
Think about what you want to do with your current home (e.g. sell it, lease it, leave it empty) and what kind of accommodation will be most suitable in your new country. If you don't know anyone in the new country who can help find accommodation, consider the services of a relocation agent.
Will you be looking for work in your new country? If so, consider starting your job hunt before you go. Will you be able to use your existing qualifications or will a period of retraining be necessary? If you're moving somewhere where they don't speak the same language as you then you should...
Few skills will have such a positive impact on your relocation experience as being able to speak, or at least understand, the local language. Getting to grips with the local lingo before you go is a great idea!
No matter how insignificant that old document at the back of the bottom drawer may seem now, take it with you, the chances are at some stage you'll have to show it to someone. Moving countries can be a bureaucratic nightmare at the best of times but if you come prepared with the necessary paperwork you stand the best chance of a stress free relocation. Things to think about include birth certificates, wedding certificates, educational certificates, medical certificates (including those for your pets!), etc.
Don't forget to inform everyone of your new address and when you're going (unless you don't want them to find you, of course Seriously though, saying goodbye to friends and family can be the hardest thing about leaving, be prepared for an emotional roller-coaster ride as the day of departure draws near.
Will you be taking everything with you or leaving some items in storage (or even getting rid of them completely)? How will you move your belongings? Can you transport them yourself or do you need the services of a moving company? Set aside those things you need to take with you in person so they don't get packed accidentally (passports, tickets, etc.)
Once you've decided what you're taking with you, insure it. If you haven't already arranged appropriate insurance (health/life/travel, etc.) for yourself and your family as well...DO SO!
You may need to open a new bank account in your new country - look for information on the one which suits you best. Do you need to close your current bank account? At the very least you'll need to tell your current bank that you're moving.
Credit card companies need to be informed you're moving. Also, will the credit cards you're taking with you be widely accepted?
Depending on where you're going and how long you're going to be there you may need to apply for a new driving license or even take a driving test. Will you take your car with you or buy/rent/lease one when you get to your destination country?
Gas, electricity, cable companies and so on will need to be informed of your departure and contracts terminated where appropriate. Make arrangements for final meter readings and bill payments.
Having your mail redirected after you leave can prevent you from missing something important.
Check whether or not your TV, video, hair dryer, alarm clock etc will work in the new country. You may need to take out a new network subscription for a mobile phone (or buy a new one with a subscription) - watch out for roaming charges with your current phone if you use it.
If moving means you can't keep your current email address, consider a free web based email account you can access from anywhere.