You NEED the Design Patterns book, believe me.
I do? Which book is that? ISBN?
by Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides
Commonly referred to as the GoF (Gang of Four) book, this is one of the "holy bibles" of software development. There may be better books for first learning about the concepts of design patterns, and there's books that do a great job of encoding these patterns in specific languages, but this is the one book on the subject you should have knowledge of, as it's likely to be asked about in any interview.
Oh, and the ISBN.