Foundations of Programming and The Code Wiki Book by Karl Seguin

See Karl Seguin's blog.
See The Code Wiki site.

You are allowed to copy, distribute and display articles, provided that you always attribute articles to Karl Seguin, do not use them for commercial purposes and do not alter in any way.

Foundations of Programming (pdf)
A new article in Foundations of Programming series called Back to Basics: Memory was recently released in HTML.
The Code Wiki Book, Chapters 1 - 2 (pdf)