Foreign lands are the stuff dreams are made of, but the most important fact that you must never lose sight of, is that many foreign countries have different languages and cultures from your own. Even if English is the second language of your intended destination, it does not mean that everyone will speak fluent English. The reality will probably be that you are going to live amongst ordinary people, doing everyday activities, in their own language. Unless you are fluent in the language of your overseas base, there are a few things you ought to consider packing:
Firstly, a translation dictionary between English and the language you will be submerged in. It doesn't matter how proficient you are in the other language, you will still find this useful, especially at first when you are settling in and becoming accustomed to the dialect.
Secondly, as much of your writer's bookshelf as you can possibly carry, or mail to your new address. I know, airlines have very strict baggage restrictions but you can easily purchase a few t-shirts and pairs of jeans/shorts once you arrive, replacing your comprehensive English dictionary/thesaurus, Writer's Handbook, Writer's Market, etc may not be so easy. Especially if you want them in English! You may, of course, purchase them via Amazon.com, but this leads onto my next piece of advice.
Thirdly, make sure you have a valid e-mail address. If possible, take a laptop computer with you so that you can have Internet access at anytime and will not feel completely cut off from the rest of the world. Trust me, after a few weeks of hearing no-one around you speaking your language, you start to feel a little isolated.
Fourthly, if you are taking a computer with you, or intend to purchase one at your destination, take the software you are going to require. You will probably be able to buy the more popular titles in the country you visit, but they will not necessarily be the English versions, and believe me, "Help" is a misnomer, when the "Help" is in Swedish!
Fifthly, try and make contact with someone in the area you are going to. Network as much as possible and find out what the place is like as a "living area" rather than a "holiday destination". For example, which days are public holidays. Find out what the culture is and you will not feel so alien.
Finally, if you can, try and make contact with the local librarian. If you are intending to do any kind of research, you will probably need to make use of the library. In Sweden, I couldn't get a library card until I had a personal number, which I couldn't get until I had a residency permit. It might be wise to contact your Embassy in the destination country prior to leaving home. They will be able to advise you on this kind of red tape.
Have a great trip