Hi Wes - here's the Website of the IWW: http://www.iww.org/ (click). The "Little Red Songbook" is available for $10 at the site. It's a great book, but most of the songs are recent and I'm not sure that's what you're looking for. There's a thread on the Little Red Songbook here (click)
Actually, you can find a lot of songs right here in the blue DigiTrad search box if you do a category search for @labor or @union or @work - we have probably the best collection of Wobbly songs you'll find anywhere. I can recommend lots of good labor and protest songbooks, but I don't know of a songbook collection of just Wobbly songs. You'll note that the IWW Website has a few CD's, most notably "Rebel Voices" and "We Have Fed You All a Thousand Years."
If you can think of any specific songs you're seeking and can't find them with a Mudcat search, post a message and ask for them specifically.
-Joe Offer-