I want to start INVESTING MONEY what are the different ways by which i can go about it in India?

Like i want to start investing money dont know how to go about it what are the different ways by which i can go about it for example have heard the word Mutual funds being used alot or words like DeMat account what are these and how can i know more about them from a lay mans point of view. I wanna know everything about them and how to get into it the risks involved as well as the advantages i can gain from them. Which bank is the best for starting on with these ventures i want it in Mumbai obviously.
Also interested in investing in gold, silver etc which is the best and most profitable form of investments.