I have decided to study Algorithms.
I have started doing this self study by first studing algorithms like Bubble sort,Insertion sort, select sort and merge sort and quick sort.
So now what should be my next step ?
I would recommend picking up a textbook on algorithms and trying to work through it. The book "Introduction to Algorithms" by Cormen, Leiserson, Rivest, and Stein is a standard text for an undergraduate-level algorithms course. You should be able to find older editions available used for not too much money. This should give you a good sense of how much you like this area of study, and whether your mathematical background is adequate. (If that particular text is not to your tastes, there are many others out there that cover similar material--perhaps some other posters can recommend their personal favorites.)
Even if you decide that you don't want to pursue algorithms academically, this exercise should help make you a much better programmer.