Books are a wonderful way to spend spare time and increase knowledge and expertise on all types of interest and subjects.
A bookstore can broaden your horizons by showing what is available and what new books are subjects of interest. Submerging yourself into a detective novel, or learning history from a compelling biography is a wonderful way to spend a few evenings. Technical Books from Auto Improvment , to HTML,  to Sewing Instruction, to Cabinetry can add to hobby enjoyment and to professional knowledge. Books on fantasy can relieve the mind of the stresses of everyday life, and Romance Novels can send to a world of your own fantasies.

Series books are possibly the most fun like Harry Potter, a very enjoyable read for all ages. I like the John Corey novels by Nelson DeMille, and I find the Odd Thomas series by Dean Koontz a wonderful  first person escapist novel.Then there are old favorite books like Zen and the Art of Motorcycle Maintenance that give life and words to common feelings, ideas that most have felt but don't know how to express. Another favorite book of mine is Walden by Thoreau that have philosophical ideas that are as fresh today as when they were written over 150 years ago (Walden usually comes with the essay "Civil Disobedience" )  that book was in part the empowerment for Ghandi's revolt in India, the peace movement in the 60's, and the independence movement in Poland that started the fall of the former Soviet Empire.

Books are often overlooked and frowned upon because of the effort it takes to read a few hundred pages, but I don't remember anyone ever saying   "Hey the Movie was better than the Book". Give me the images in my mind of the Lord of the Rings over the movie anytime. The movie was good, but it missed sooooo much that was in the book. The books tend to have more  details and those details that a book  can not deliver can be conjured by the imagination. That is the real power of books.