Websites for Learning

https://github.com/JohnTortugo/Algorithms
http://theshayna.com/data-structures-and-algorithms-tutorials/
http://leetcode.com/
http://learn.hackerearth.com/
http://www.geeksforgeeks.org/
http://www.careercup.com/
http://www.topcoder.com/tc?d1=tutorials&d2=alg_index&module=Static
http://www.cracktheinterview.net/forum.php
http://courses.csail.mit.edu/iap/interview/materials.php
http://www.techinterview.org/
http://www.techinterviews.com/
http://www3.cs.stonybrook.edu/~algorith/video-lectures/
http://www.chiprime.com/static/lessons.html
http://www.ardendertat.com/2012/01/09/programming-interview-questions/
https://learn.hackerearth.com/
https://sites.google.com/site/steveyegge2/five-essential-phone-screen-questions

Specific by Company

Problem Sets & Judges

http://www.spoj.com/
http://uva.onlinejudge.org/
http://uva.onlinejudge.org/
http://medhavi13.blogspot.com.br/2011/12/quant-interview-questions.html