Whenever you find some field or topic interesting the chances are you can find some book, blog, or newspaper articles on the topic and research into it yourself. It doesn't even have to cost money if you make use of your local library. Also, because it's just a hobby you don't have to worry about understanding or being good at anything, although I think that trying your best to understand definitely enhances the experience.
Doing this also prepares you for the future as you'll have a wider breadth of knowledge and connections to draw on, as well as strengthening your researching skills.
