This book was written for all Delphi programmers. It doesn't matter whether you are a beginner or an expert this book is for you!
While a basic knowledge of Delphi programming language and IDE is definitely a boon, you can read this book even if you know nothing about Delphi. The Pascal language is simple to read and understand, and when we come to advanced topics, the book explains the Delphi syntax with clear and simple examples.
The only requirement this book has from the reader is that they like to explore and learn. This is not a when this happens, do that kind of book. It explores interesting topics and gives insights and sketches of solutions, but doesn't contain any recipes claiming that this is the only proper way to do X.
This book will teach you to think, not how to reuse code.