Since you should already have a bachelor's degree when applying to graduate school, you should already have a good idea of the academic area that you plan to focus in. Therefore the next category to narrow your search is location. Think about if you would prefer to Eastern vs. Western Europe, Scandinavia vs. the Mediterranean, etc.
With academic subject and location in mind, head to www.mastersportal.eu and www.study-info.eu. These two websites are by the best way to begin your search for a graduate degree program in Europe. You can search by keyword, region, or discipline and find direct links to the programs' websites.
After exploring the above websites in depth, head over to the list of Erasmus Mundus Masters Courses at http://ec.europa.eu/education/programmes/mundus/projects/index_en.html. This is a list of mostly two-year programs in a wide variety of disciplines that are sponsored and funded by the European Union. All-inclusive scholarships are available for all of the programs which are attended by students from all over the world.
After devoting a good amount of time to those three websites, make a list of potential options and research each of their individual websites to see if it could be a fit.
If you still need more options at this point, this is when you can get creative with your google searches. I spent many hours figuring out different ways to search what I was looking for and ended up finding several very exciting programs to apply for.