Daily Cartoonistreports that the Salem, Oregon-based cartoonist and writer about comics Arnold Wagner passed away last week after a recurrence of cancer. Wagner was perhaps best known as a co-author of The Complete Idiot's Guide to Cartooning and as a co-founder of the 1960 magazine The PRO Cartoonist & Gagwriter. He was also an active presence in many cartooning communities, and kept an eclectic comics-related blog. According to a biographical post excerpted here, Wagner worked mostly in "gag cartooning, advertising and illustration."
I will supplement this post with better information as I'm able to discover it.