Aloha!
I have online searched far and wide, and can not seem to hit on the proper website link to access the song books for the Dallas Ukulele Headquarters. Somehow, I was able to download their song books a few years ago, probably in 2011.
Since I can’t find any online access to them, I am going to temporarily provide the download PDF on my site, until I can find the proper link to put here instead.
Dallas Ukulele Headquarters Beginner Jam Book
Apparently, this is their website: http://www.meetup.com/ukulele-84/
Cat's Ukulele Songs 