I have read so many types of theory and even read more about investment rules. but it is still only words and a theory.
In order to become a good trader, we not only need to read, we need to practice to test whether our transactions are right or wrong.
From there we will have experience and we will do a lot better than those who only read books.
Usually to read is very helpful and it can help you to understand also, because you will get more ideas. While you read, it needs to study it and try to apply in trading. So its easier for you to know if what can you do the best to make you success in trading.