Books, even bad books, can provide a spark that set ideas aflame.
I read a lot of books and try to read a good mix of fiction and non-fiction. Generally, the ideas come from the non-fiction books, though not always. Business and creativity books work best for me. Often I’ll read these in the hope that something sparks and lights a fire.
The same can be said for other types of reading material. Read articles, essays, research, blogs, whatever it is that works for you.
It’s not about how good the book is. It’s about finding that suggestion or piece of information that triggers a tangential thought. That’s the spark.