When it comes to developing an appreciation for world music, the first question is always "where do I start?" Which styles, which regions, which artists, which eras... The world is big and there's a lot of good music in it, and this stuff isn't always easy. But once you've crossed that boundary, it can be just as hard to figure out where to go next.
If Celtic music is on your radar but you're just not sure exactly how to expand your fledgling collection in a focused way, let me help you out: How To Build a Celtic Music Collection