1）编程练习和竞赛类

http://www.codechef.com/
http://www.spoj.com/p/
http://programmingpraxis.com/
http://projecteuler.net/about
http://www.topcoder.com/
http://codeforces.com/
http://www.hackerearth.com/
http://www.pythonchallenge.com/
https://www.hackerrank.com/
http://leetcode.com/

2）教程类

http://www.learnstreet.com/
http://www.geeksforgeeks.org/
http://www.codeschool.com/
http://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign
http://www.stanford.edu/class/cs97si/
http://pratikpoddarcse.blogspot.in/search/label/EasyPuzzles
http://sbjoshi.wordpress.com/
http://www.good-tutorials.com/

3）社区交流类

https://www.quora.com/
http://stackoverflow.com/
https://github.com/
http://www.careercup.com/page
https://geekli.st/
http://www.reddit.com/r/programming/