Part of your learning process must include at least one book on poker It will give you a foundation on which to build your expertise. Two books are better than one. The reason is because that no two writers are likely to agree on any given topic, and a difference of opinion will make you research which one is correct. You will never forget whatever you took the trouble to find out for yourself, it will be branded into your brain.
David Sklansky's books are as good as any.