If you are getting into compiler construction today, you will see a lot of "cutting edge" stuff which discusses minute details of optimization but assumes you are already versed in the art. You may also see a few "baby books" that don't require any real background but also don't give you any real depth. This is the Standard reference on compiler construction. It assumes you are familiar with programming, and it gives you enough tools and techniques to write good compilers. More importantly, it is the book that will give you the grounding in terms of art and technique that more recent works require for comprehension. In short, this is the book that can take you from knowing programming to knowing how to build compilers. There are cutting edge things it doesn't cover, but it gives you the knowledge to understand them when you get to them.