This book has (understandably) recieved a lot of criticism from past reviewers, who bought this book hoping to master the basics from scratch, without requiring any previous language study. Afterall, this is what the book promises. However, the reader is thrown into complex paradigms, confusing tables and in-depth grammar rules from the outset. I myself, a final year language student at university, struggled to fathom out some of these paradigms. And as for no previous language study... a good knowledge of German is needed just to gain full benifit from the pronunciation section!
However, this is not to say that this book does not have it's uses. The grammar explanations (paradigms and diagrams aside) are very useful and concise and have helped me to bridge those gaps in my knowledge. Furthermore, this book does actually teach the colloquial language, so you will understand the language the people actually speak, not just the language the text books use.
All in all, this is a good book... just not for beginners. My advice for anyone interested in buying this book, or indeed in learning Finnish, is to buy Teach Yourself Finnish by Terttu Leney and then move onto this book afterwards. It will improve your Finnish, polish your grammar and teach you less stilted Finnish.