How literate is your fictional world? What is done to encourage the reluctant reader or is reading something that is reserved for the political classes and "peasants" aren't allowed to read at all because it might give them ideas? (Reading almost certainly does give ideas! Ideas for other stories for one thing!).
Are there libraries and, if so, can anyone access them? How easy would it be for your main character to get to a library to say access important, ancient documents to help them in their quest? Do your characters read to relax or research or both? If a book they need is banned, how do they get around that ban to access the volume?
Is reading encouraged in the villages and small towns of your fictional world or is it viewed with suspicion? (Character X is getting above their station with all their book ideas etc etc). The better a picture you can give of your fictional world, the more real it will seem to your reader and the longer lasting the impression it will have. Details like these points can help make that world seem more real.