Seniors have eye problems. Thus large print books, e-readers and tapes are a great free source. Especially for best sellers, where the waiting list may be, 291st of the first 3 copies returned. You may want to turn to the large print shelf, which may have a much shorter wait. These books are also much easier for old eyes to read.
In addition, take a look at free e-readers, in a variety of brands, such as Kindle. You can usually check them out from a distance for a few weeks with a library card. There are a limited number, so you may have to wait here to, but usually the wait is not so long. E-readers also have the additional advantage that you can make the type larger.