Preparing to go abroad includes securing important documents, making copies, and a lot of planning. Ideally, you should make 3 copies of your passport, visas, and other important paperwork. Keep one with you, one in an accessible but safe place (i.e. safe deposit box), and one with a trusted relative or friend that can retrieve the information if something were to happen to you or the other copies.
A checklist of other things to consider:
Make sure all bills are paid or have a means of being paid while you are away. If you are retaining a residence while abroad, make sure the rent/mortgage is taken care of and that utilities are being paid while you are away. Insure that important institutions like your bank are able to reach you.
If you are retaining a bank in your home country, ask about fees for overseas transactions. If you have a credit card, find out if there are additional fees or any changes you need to make with your account. Inform banking industries that you will abroad so as to not arouse suspicious activity on your account as anti-theft systems can see this activity and put a most inconvenient hold on your account.
It is best to inform tax offices of any change in residency. Some countries have reciprocal tax agreements, and others may require you to pay some form of taxes both in your home country and aboard. Most National Tax Administrations are an excellent resource for exactly what steps to take when moving away.
All travelers are recommended to have their routine vaccines. Some health organizations recommend a Hepatitis A shot since it can contaminate food or water in Hungary, regardless of where you are staying. Some travelers also receive Hepatitis B and rabies shot as a precaution, but it is not enforced.
For concerns about your health when abroad, the World Health Organization (WHO) publishes International Travel and Health, which is revised annually and is available free online. Another excellent resource is MD Travel Health. It provides free, complete travel-health recommendations for every country and is updated daily.