The "Dvorak for left-handers" layout is for people who have no use of their right hands, as distinct from two-handed people who use their left hands for writing etc.. I mention that, because the name of the layout is ambiguous.

I found diagrams and related information for one-handed typists at

http://home1.gte.net/bharrell/kbdtxt.htm

The two-handed Dvorak layout is described at

http://thisistrue.com/dvorak.html
http://www.dcn.davis.ca.us/~sander/mensa/dvorak1.html
http://www.mwbrooks.com/dvorak/

There is a course on the subject at

http://www.mit.edu:8001/people/jcb/Dvorak/dvorak-course/