Stock market and investing in startups and businesses allures many,  but it takes a great determination and devotion of time to make money out of it. You have to study the business model, understand their markets, the company's future plans etc. Another aspect is that whether what the company does is viable and will their business hold in the long run. Whether their profits are increasing, look at their balance sheets and what steps is the company taking to reduce their debts and acquiring new assets, that will matter in the long term.
I have been reading about these kind of things and let me tell you, this has actually been a turning point in my life. The knowledge of these matters and their real world application is amazing. It always amazes me how any ordinary person can look at the local businesses around and simply identify the ones that seem promising and invest in them. One book that taught me this is "One up on the Wall Street" by Peter Lynch. It is a wonderful book that teaches that its not only the wall street guys that can make a killing in the wall street. It is a book understandable by anyone who knows about the stock market and investing in general.
As an even basic book I do recommend reading the book "Rich dad poor Dad" by Robert Kiyosaki first. You will surely thank me after reading it. It is one gem of a book that every person and every college going student must read.