Jan H posted some great links in this thread...
I'm sure there's lots of other great info there as well. It's a really simple cake to make and ther rice paper is super easy to work with! Lots of luck with this cake!!
I have done one. Cut your feathers about 1 - 1 1/2 inches wide at the bottom, tapering up giving the feather look. Each tier will hold 3-4 layers of feathers. I found it easier to keep the feathers all as one sheet instead of seperately.
Attach with either RI or piping gel.
Keep in mind that after a couple hours, the feathers droop.