I would agree with the sentiments of the comments above. True, it is a heavy-going book, but that's the point. Object-orientation isn't the easiest subject in the world to master but this will help you on your way. Personally, I found the book extremely useful as a reference rather than one that would be read from cover-to-cover. A case study is used throughout the book to try and show the implications and reasonings behind the decisions that OO A&Ds will make. For those new to the area, or if you are an undergrad, read this after the UML Distilled book by Martin Fowler, and you will then get the maximum value out of it.