I still think the best book on Esperanto instruction I've read so far was the Teach Yourself Esperanto, 3rd Edition. I thought the instruction in this book was fine, and there were a few lessons that helped clarify a few grammar rules. The biggest benefit of this book, in my opinion, was the second half of the book, which was an Esperanto reader. It was helpful to see the language used in passages that were not just short, basic sentences used for instructional examples.