A valid identity card is sufficient for member countries of the European Union, but a passport valid for 6 months after the end of your stay will be necessary for the rest of the world. If you are going as a family, note that your cherubs will need their own passport. Please note that the deadlines are approximately 3 weeks and may be extended as the summer holidays approach. Some countries require a visa. Again, delays can reach a few weeks. Finally, countries such as the United States, Australia and Canada (from April 2015) require an electronic travel authorization which can be obtained in less than 72 hours via the Internet. Be careful not to forget this step or you won't be able to get on the plane!
One month before departure, ask your doctor about the illnesses and any necessary vaccines. Prevention is better than cure (and ruining your vacation). Also remember to apply for a European health insurance card or take out insurance (already included with Visa Premier or MasterCard Gold). Check with your bank that you can withdraw money from ATMs abroad and any fees that go with it. Provide euros and banknotes in local currency, or even travellers' cheques. And, if possible, carry two payment cards. Always useful in the event of a glitch, loss or theft.
A few days before leaving, remember to photocopy your travel documents:passport, plane tickets, hotel reservation and, ideally, store the photocopies in your mailbox. Two copies are better than one. Finally, pack according to the climate and the activities planned for your vacation. No need to overload yourself. The minimum is often more than enough.