Want to really learn how to knit mittens? Knit Mitts --Your Hand-y Guide to Knitting Mittens & Gloves is the book for you. There are plenty of patterns for mittens and gloves and fingerless gloves that feature cables and colorwork and all of the things that make you want to knit them in the first place, but what really makes this book shine is the fact that it explains how they all work.
Have you ever seen the extremely complex discussions about how to make socks fit properly? This book does that, except it's how to fit your hands. I had no clue that there were so many parts to measure!
There are instructions for working to your own measurements, charts for different ages and hand sizes and stitch counts, recommendations for yarn types and techniques to keep your fingers extra warm... Honestly, the only thing missing is discussion of traditional mitten styles -- and there are already tons of books out there that have that part of the craft covered.
If you want to do more than just follow the pattern, you'll love this book. And if you want to just follow the directions as written, you can use the included patterns and make the gorgeous projects shown on the cover.
Disclosure -- I was provided with an advance review copy by the publisher. All opinions are my own.