Lists:

1. GeesForGeeks:  http://www.geeksforgeeks.org/

2. LeetCode:   https://oj.leetcode.com/

3.Visualgo:  http://visualgo.net/ (including some dynamic animations)

4.Wikiwand:  http://www.wikiwand.com/en/

book:

<<Introduction to Algorithm >> 

Resource for learning Algos