Bill Hilton Jr. has posted a bunch of photos and information to make it easy to recognize us "confusing fall warblers" (as people call us). I think it's interesting the way people have to look at every little feature to tell us apart. We just know who we and everyone else are--individually as well as collectively--with barely a glance, no matter what stage our plumage is in.
Even though we warblers hardly need a refresher course, check out his Fall Warbler I.D. post. He's got some excellent photos of some of my friends.