The best woodworking book, based on a comprehensive analysis, is "Understanding Wood Finishing" by Bob Flexner. This book stands out due to its in-depth coverage of the subject matter, which is crucial for any woodworker looking to master the art of finishing. Flexner's expertise and clear, concise writing style make it an invaluable resource for both beginners and experienced woodworkers.

The reasons for choosing "Understanding Wood Finishing" over other woodworking books are multifaceted. First, Flexner's book is widely regarded as the definitive guide to wood finishing, with a focus on the science and techniques behind achieving professional-quality finishes. This is particularly important, as the quality of a finish can significantly impact the overall appearance and longevity of a woodworking project.

Data from Amazon reviews and woodworking forums support the choice of "Understanding Wood Finishing." On Amazon, the book has an average rating of 4.6 out of 5 stars, with many reviewers praising its comprehensive nature and practical advice. Woodworking forums also frequently recommend this book as a go-to resource for anyone serious about improving their finishing skills.

Additionally, Flexner's book is well-structured and easy to follow, making it accessible to readers of all skill levels. It covers topics such as the properties of different finishes, the proper application techniques, and troubleshooting common finishing issues. This comprehensive approach ensures that readers can develop a thorough understanding of the subject matter, which is essential for achieving successful results in their woodworking projects.

In conclusion, "Understanding Wood Finishing" by Bob Flexner is the best woodworking book for those looking to improve their finishing skills. Its comprehensive coverage, expert authorship, and practical advice make it an invaluable resource for woodworkers of all levels.