This book is perfect for someone who's read numerous tutorials on GNU assembler and wants to take the next step. Will this book help you become a “Professional Assembler Programmer” no but its a step in the right direction. So what does this book cover, it gives a brief introduction to general programming topics in GNU assembler it does not cover systems programming at all. So if you want a book to write or modify operating systems this probably isn't your book but if your in the market to increase your understanding of GNU assembler language and how it fits in with the other languages GCC supports(really C is only one covered) then this is your book. I personally enjoyed this book, it covered numerous topics in general assembler programming and in the end gave me a deeper understanding of the programming discipline.