Maybe try fiction books that are in a similar subject area to non-fiction books you enjoy. If you like history read historical fiction, if you like travel books read a book set in a place you've read about. If you're sort of familiar with the setting/background that could be less you have to visualize.

It's sort of backwards from my usual suggestion, but if there's a movie try watching that first. Then read the book and your brain will probably automatically think about the movie descriptions and characters, so it might be easier to get in to.