These days, the word "hobby" evokes a sense of blase interest. Children have hobbies; bored housewives might have a hobby or two; the rest of us can scarcely be bothered. The original connotation was much different, however—a person's hobby was their avocation, not a primary sense of income, but certainly the focus of passion and interest.
To put it in perspective: Rene Descartes was a mathemetician by trade, but his hobby or avocation was philosophy. Not everyone with a hobby is going to change the course of Western civilization, but the point is that Descartes' hobby wasn't a mere back-drawer doodad he pulled out when he was bored and lonely, it was a motivating force in his life.
We're not suggesting hobbies need to take over your life, like robots in some creepy sci-fi movie. Just the opposite, in fact—hobbies should keep us from surrendering to the doldrums of existence, make us excited, provide an opportunity to exercise our creative talents and explore our interests. They shouldn't be simply a way to pass the time, because that's just another name for boredom.
At the same time, making your hobbies (whether they include cooking, weaving, woodworking, book-binding, or origami) the focus of all your attention is just as harmful. If you find yourself only working to fuel your interests, your hobbies (however harmless they were to begin with) have become your idols and you need to put them aside and learn to prioritize. Still, you need to have interests outside of work, and they need to be cultivated and not just casually dabbled in from time to time.
Why do we take hobbies so seriously? Because what we spend our free time doing reveals a great deal about who we are. If your primary activity when you aren't at work or cleaning the house or whatever is buying clothes, then clothes are what's important to you. The same is true for playing video games, watching reality TV, and bare-knuckle boxing.
It's important to choose hobbies that are constructive. As Christians, we're to do everything to the glory of God, and while some activities done in moderation might be fun, doing them all the time is more a sign of selfish addiction than simple enjoyment. Hobbies should be relaxing, of course, but they should be good for something, and good for other people.
The books you'll find below won't tell you what your hobby should be. They will, however, help you develop the skills related to certain hobbies so you can pursue them to the best of your ability. In a world that excuses lack of excellence and even defends poor quality, we need to work even harder to do our best, whether in our vocations or our avocations.