When entrepreneurs ask me where to find good ideas, I advise them to read promiscuously and make connections.
(No, this isn't some kind of advertisement for Tinder or Grindr.)
To read promiscuously means to be voracious and unselective. I was at the library on Sunday, looking for audiobooks, and as usual, I picked up a selection. I don't just listen to business books (though I do like them--it was great when I was a student at HBS and could raid our business libraries). I almost always check out a broad assortment, including histories, mysteries, travel books, and many more.
If you tell me that you read for two hours a day, I'll get a good impression. If you follow up by telling me that all that time is spent on TechCrunch and Hacker News, I'll lose that good impression. You can't get interesting ideas by reading what everyone else reads.
To make connections means to read actively, rather than passively. As I read, I'm constantly thinking about implications, identifying similarities, and trying to generalize to situations in my own life.
This has always been the issue with how we teach literature in this country--we treat literary analysis as an academic discipline. And while it's cool to be able to explain how crop yields help explain Chaucer's choices in the Canterbury Tales, literature matters because it is universal. The reason we think a great book is great is because it's relevant to our own lives.
Relevance is in the eye of the beholder; the more relevance you see, the more interesting ideas you'll have.
Now go out there and read.