A recent look at "tenor guitars" which were largely designed to transition jazz banjo players into jazz guitar players taught me a bunch of stuff about Irish, tenor, and plectrum banjos that I didn't know before. So I started a new forum JUST for tenor banjos here. And I expanded the description of different kinds of banjos on CreekDontRise.com. http://www.creekdontrise.com/acoustic/b ... banjos.htm
In addition, I've added a lot about tunings and string gauges to our 4-string banjo buyers' guide at RiverboatMusic.com. If you haven't checked out our "buyers' guides," you should. We don't just list random products we found on the internet. Instead we tell the uses, features, and differences of each category of instrument we discuss. If you make an uniformed purchase of any instrument we've covered, it's not our fault.
At any rate, here's the expanded 4-string banjo buyers' guide:http://riverboatmusic.com/banjos/four_s ... banjos.htm