Programming from the Ground Up Book
savannah.nongnu.org
savannah.nongnu.org
http://www.ibm.com/developerworks/search/searchResults.jsp?s...
Covers various things including PPC assembly language, PS3 assembly language, using high-level programming techniques in low-level languages, and other fun stuff.
http://download.savannah.gnu.org/releases/pgubook/
Or if you prefer the dead tree version:
http://www.amazon.com/Programming-Ground-Up-Jonathan-Bartlet...
"Ground Up Programming Book" ;)