I like the books "Don't make me think" and "Designing the obvious" for some basic web UX knowledge. They are short and to the point.
Also, I'd throw in The Design of Everyday Things -- see http://www.amazon.com/Design-Everyday-Things-Donald-Norman/d.... It was written long before anyone ever thought of web usability; instead, it focuses on the usability of things you interact with daily in real life. Let's just say that you'll never look at teapots or door handles the same way again...