I have over 20 lettering books in my collection, but the first one I ever got was Reinventing Lettering, edited by Emily Gregory. This is also available as Little Book of Lettering.
When I was starting out, I did not know which style to pursue at first. Having a reference with different type artist working with various materials definitely helped me narrow down my options. The book has three chapters: computer-generated graphics, hand-drawn type, and 3D. I resonate mostly with the second section, but I regularly turn to the other two when I am stuck in a rut or when I am in the mood to experiment. I recommend this book to beginners because the artist index alone leaves you with plenty of subjects to research and styles to try.