http://www.theatlantic.com/technology/print/2011/06/how-i-failed-failed-and-finally-succeeded-at-learning-how-to-code/239855/

http://community.topcoder.com/tc?module=Static&d1=tutorials&d2=alg_index

[ machine learning class ]
http://www.cs.cmu.edu/~tom/10701_sp11/lectures.shtml