[ale] Pointers to Information?

[lodi at mindspring.com (lodi at mindspring.com)]

Hey all, this is a semi-Linux related question.
I really would like to start learning about programming for
X-Windows. I've found some shabby sites on the stuff. Haven't really come
across anything real promising, except the references from ftp:mit.
However, I think those are too advanced for me. 
I prefer an introductory book that covers X11R6, goes in-depth and doesn't
treat the reader like a dumb-ass. The only ones that seem to fit the bill
are some I found printed by O'Reilly, but they were on X11R5.
Does anyone know any books, sites, or whatever that you think would be
good? Any and all pointers would be greatly appreciated.
Thanks ahead.

Regards.