Brian's book, Mastering Riddles, Puzzles, & Mazes, has been super helpful in growing an area of my GMing style that hasn't been a strength in the past. It's something my kids are pushing me to expand on and incorporate more of in our D&D campaign. His thought process describing how to use puzzles and riddles is thoughtful and easy to understand.
A strength of the book is how Brian provides loads of concrete examples you can us in your own campaigns. I find that kind of in game learning to be really helpful, and should help me grow more confident developing and using my own puzzles in the future.
I can't recommend this book enough if you want to learn how to include more puzzles in your games!