Learning how to design a circuit to do something that you want it to do is one of the ultimate products of an education in Electrical Engineering. For your situation, my suggestion would be to study the basics and look up projects that others have come up with. If you can figure out why the circuits work, you can sometimes modify them to your needs.
Being a Computer Scientist, you might also be interested to pursue digital electronics and embedded systems. You can program a microcontroller to do just about anything.
I don't know if Forest Mims will be readily available in India. However, if you can import, you can get it from
Amazon.com.