When traveling to Europe make sure you have a valid passport with you. Your passport validation must last at least for six months before you travel abroad.
To enter into Schengen area (that consists out of 26 EU member countries) for travel up to three months, business trip or transit to a non-Schengen destination, your passport must be valid for at least three months beyond your intended date of departure. Check here for more detailed information.
Make sure you have at least one blank page for entry stamp, however, some countries require to have two blank pages. For a country specific information check here
Although similar requirements are valid for most of the area countries, they may vary from country to country. It is advised to consult embassy of consulate of the destination country for further details.