This book is pretty good, considering it's put out by Llewellyn..
It covers the origins of ogham, the levels of the trees & then goes tree by tree, working with the physical, mental & spiritual level of each tree. Best of all (as far as I was concerned), it gave you practical working advice for each tree; what you can specifically use that tree for to enrich your life.
All & all, well-written and great for beginners.
Steve Balmires' book is a well-researched and comprehensive treatise on the Tree Ogham. It also contains complete instructions on making your own Ogham sticks. Following these instructions is not an option for everyone. With careful planning, shopping, and preparation, you might be able to complete your set for under $10,000 and in less than six weeks. Depends on how many of the plants you find nearby. You will definitely have to travel to the UK and spend an extended time there. But it is possible- for a few very wealthy pagans. Still, a very well-researched and otherwise useful book.