"There are certainly cases where applying objective measures badly is worse than not applying them at all, and education may well be one of those."
-- Nate Silver
by Brad Miller and David Ranum, Luther College (as remixed by Jeffrey Elkner)
by Mark Guzdial and Barbara Ericson
Hands-on introductory computer programming using Python 3.
by Peter Wentworth, Jeffrey Elkner, Allen Downey, and Chris Meyers
An introductory computer science text book using Python.
by Tony R. Kuphaldt
A free series of textbooks on the subjects of electricity and electronics