Deep Learning with Python by Fraincois Chollet is an excellent book to begin or refresh your deep learning journey. Under $30, it is a high quality purchase that will take you through clear examples and go over the concepts clearly with little theory or math. Unlike more advanced machine learning books that are filled with theory and math, this book avoids a lot of that so you can get up and running in just over 300 pages. We highly recommend this be your first book into Deep Learning and Neural Networks.