The Stranger follows the "adventures" of Meaursault, a French-Algerian, as he tries to make his way through the Universe in a life he neither asked for, nor understands, but is doing his best to navigate. The action is muted and secondary to the motivations and thoughts of Meaursault and the revealing of Camus' philosophy.
If you haven't read anything else by Camus, you probably had to read The Stranger in high school. But now may be a good time to give it another chance. The novel falls into three parts, each marked by a death. Straightforward and simple, the novel presents its plot clearly enough, a good foil for the philosophy of the author. Camus said of this book that it portrayed "the nakedness of man when faced with the absurd" and every life is absurd. Meaursault is not what you would expect as the hero of a novel; he is just an everyday guy, perfect for the role, really, since his job is to reveal the author's version of the truths that are universal, not applicable only to a few. As an atheist, he has no preconceptions about his life or the direction it should take and is at the "mercy" of the world.
An Existentialist, Camus is not always a bundle of laughs to read, but always has interesting commentary to make about the world and the importance of accepting who you are and learning to deal with your true strengths and weaknesses. It isn't saying you should be this or that, but saying that you should just be. Don't concentrate on becoming some other person's version of success, because, after all, we're all just going to end up dead anyway. A kind of Existentialist carpe diem message for anyone who has ever felt like a stranger, and that's probably everyone. As Meaursault himself would say, "the truth shall set you free." It is a difficult read in some ways, but it will leave you changed.