I bumped up a thread for you called "Educating Styles" that has a wealth of links on different styles. There is a ton of information there!
I found it helpful to hang out on message boards and listen to people talk about WHY they like what they like. It also helps to see the things you are thinking about buying before you buy them, but that isn't always possible. I think the most important thing to consider is if something is a good fit for your child.
I distrust people who think there is one right way, and that the same resources are perfect for all kids.
Depending on what sort of countries you will be living in, you may need to do far more advanced planning that some one homeschooling in a urban area in the states. It may be hard for you to find books in English, there may not be a good library, mail delivery may be quite slow (or totally unreliable, depending on where you go), there may be substantial duties for importing school materials, and you may have difficulting finding basic things for science experiments (things you could find in any WalMart!)
Sonlight was designed to be used by ex-pats, so you should take a look at it.http://www.sonlight-curriculum.com/
It is a christian curriculum, but by making a few substitutions I think it could work no matter what one's beliefs.
We've lived all over and it is an education in itself. My kids are young and we don't do unit studies or anything like that, but they've learned a great deal from us just doing what ever there is to do wherever we are. Now that includes things like hiking in the desert and visiting old spanish missions and settlements. This time last year we were in Canada -- so our weekends were spent at winter festivals sliding down huge ice slides in rubber tubes, going to a sugaring off, and a horse drawn sleigh ride through the woods. We aren't studying different places so much as just trying to enjoy them!
We are relaxed homeschoolers and spend a little time most days on lessons, which focus on the 3 Rs and are quite short and very relaxed. We read lots of good books together, make art, play music, and spend as much time outside as possible. What we do works well for us. We've tried different things and this just feels right for now. Something different may work better for us in six months. The advantage is that we can flow one day at a time without feeling like we have to fit into someone else's idea of what we should do, or what pace the kids should learn, etc. I think you just have to try different things and see what feels right.