That's one of my Wife's favorites, and a frequent request around the campfire.
It's really one of the easier ones, for as pretty as it is. Although no doubt I'm cheating a bit, I get away with just two chords through the whole thing - I use D and A7 i think, although there are a few quick back-and-forth changes in there and if I'm not right on top of my game I'm apt to get them mixed up occasionally. Of course you can use any chord suitable to the key which works best for you, and it's relative 5th (I think - never got a Degree in this stuff)... ie. "C" and "G"- make it a 7th just for good measure; on a "G" just pick up off of the first string - etc..
A gentle fingerpicking style works for me, but this is one of those generic tunes that will work with a variety of techniques. Enjoy!