I recently orchestrated two major international vacations with only a minor (ahem, perhaps substantial) amount of help, and let me tell you -- it was a ton of work. Between passports, international drivers permits, immunizations, reservations, state department advisories, travel constraints, dietary restrictions and itinerary considerations, there was a lot to juggle.
If you find yourself wanting to go on a big vacation and have no idea where to start, you might want to consult a travel agent. Large-scale organizing isn't for everyone, and the last thing you want to do is find you (and, god forbid, your family as well) stuck in a bad situation in a foreign land. But there are lots of ways to make the process easier even if you don't want to go to a professional. Be sure to start well in advance and always remember: A good, thorough list is your best friend. Don't be afraid to let that list -- and your itinerary -- evolve as you learn more about your intended destination.