If you're planning to invest heavily in stocks then you may want to do some training course to ground you in the basics....I'm not sure a book will give you the depth of understanding that you may need. I studied Financial Strategy (B821) with the Open Universityas part of an MBA. Tough, course but rewarding. What I learnt from that course could be summarised as follows: diversify, diversify, diversify. However, if you still want to invest in indivdual stocks I would advise you to really understand the workings of that company, understand its accounts, its people, its strategy and its ability to innovate. A lot of hard work....yes. That's why its best to track a market and by doing so you diversify, diversify, diversify !!