My first tutorial! Yaaaaay!!!
So this is for anyone who is intimidated by feathers, even though they are really, really easy. More information (LOTS more) can be found in the Animal Anatomy group: [link]
The best and most informative wing tutorial I have found is by The Antimony Element, and can be found here: [link]
Shell has a great tutorial on insanely detailed painted feathers (and fur) here: [link]
AuroraCarina-Chan has another good wing tutorial, and although it focuses on angel wings, it's very informative for one of the first lines in it: wings are arms [link]
Also, watch "The Wild Parrots of Telegraph Hill", not only because it is basically *G* in the form of a movie, but also because there is excellent close-up footage of birds doing all kinds of things even I didn't know they could do.
As for just how much perceived "bulk" feathers can add, check this out: [link]
Finally, for more inspiration, check out this gorgeous gallery of feathers at National Geographic: [link]