sorry to be an ASS
but.
does anyone nows a good book By Sartre ?
and the major diference betwen Sartre and Camus ?
I don't know who Camus is but Satre, if I take it to mean Jean-Paul Satre was an existentialist. The only thing I've read a piece of, it was part of an anthology, was "Existentialism is a Humanism", it was delivered as a lecture but was published a year later.
I saw Thus Spoke Zarathustra earlier, but I suggest to not plunge into a thinker right away, get a nice introduction to the subject. As you will find that the ideas that are brought up are part of a dialogue that spans as far back as recorded history.
Such as if you're looking into Satre it pays to know some of the thinkers that came before him, Hegel, I think though I have not read him, is important, Kierkegaard and Nietzsche, and definitely Kant. But to understand Kant, and he wasn't really good at explaining himself, you had to have some knowledge of Hume, Locke, Berkely and Decartes. And Decartes, going as far back as Aristotle and Plato, and Plato, Parmenedes, Heraclitus, and going to the Sophists. The sophists are particularly important because a lot of what is being talked about now, especially in modern day academia is dealing with the issues that the Sophists brought up, that is, there is no truth, meaning that there is no answer to the question "What is truth?".
Well, take care in your readings, but I stress that it's best to get an introductory book before really delving into specific thinkers, if you don't it will be difficult to place them into historical perspective.