For instance, it is always a good idea to register with the State Department, just in case of an emergency. The State Department can get in contact with you if something goes wrong back home or if you have problems while you are traveling.
You need to make sure that your passport is entirely in order as well. Make sure it is signed and that all the sections for emergency information are filled out. You also need to find out whether or not you will need a visa while you are traveling.
Also concerning your passport, make sure that you leave copies of its data page as well as your itinerary with members of your family and your friends.