Wiki is usually a good place to start, because of their links.

http://en.wikipedia.org/wiki/Archimedes'_screw is their article.

http://www.mcs.drexel.edu/~crorres/screw/screw.pdf is a link at the bottom which gives some of the math.

Also this site: http://www.math.nyu.edu/~crorres/Archimedes/Screw/optimal/optimal.html has some good material.

Good luck!

The only text is:

Archimedian Screw Pump Handbook. 1988 .

By Masch -Ing. Grerhard Nagel .

ISBN - 3 - 7625 - 2613 - 3 .

Regards !

Check out also the double pipe (2 parallel pipes to within 6' of bottom of any depth water source) with acompanying 'footpump' (the footpump has no moving parts and is really an orifice specially designed to let water form pipe 1 to create a suctioin as it goes back up to the surface water pump. THis design is neat because it theoretically can pump water from any depth with minimal engine force on the pump which is located at the surface (in the house). The water in pipe 1 (pumped down) acts as a counter weight to the water going up in pipe 2 (suction created at footpump inside the well).
At least thats the rumor. ??

http://www.washingtonpost.com/wp-dyn/content/article/2007/11/23/AR2007112301612.html?sub=AR

Good picture. (in laymans terms).