"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 Jeffrey Elkner (with liberal borrowings from the work of Allen Downey,
and Peter Wentworth
An introductory computer programming text book 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