An immense and valuable introduction to neuroscience.
At around 600 large pages with plenty of illustrations, this volume gives the reader an excellent start to the subject of neuroscience. It covers the ground from the building blocks of the brain, neurons, to the considerably more opaque topic of consciousness. With respect to the latter, the book introduces the Global Workspace Theory of consciousness too.
Link to book: https://www.waterstones.com/book/cognition-brain-and-consciousness/bernard-j-baars/nicole-m-gage/9780123750709
You might also wish to browse other neuroscience books: https://www.thesentientrobot.com/category/neuroscience/neuroscience-books/