For years, I have been following up comments C. S. Lewis made in his published letters and elsewhere, to read books like, say Margaret Kennedy's The Feast, which I might never have heard of otherwise, but got hold of and liked a lot. He's not real strong on books published since 1963, I admit, but then there were a lot of books published up to that year, and not all of the ones worth reading are still well-known. He probably is the main tipster for reading for me. Next month a book on the books J. R. R. Tolkien owned should be out. I imagine that will lead to further raids on abebooks.com.
I have a few living friends whose recommendations I'll at least consider. One friend recommended Robert Coates's short story "The Hour After Westerly" (you can find it in Ray Bradbury's anthology Timeless Stories for Today and Tomorrow). Another ecommended Lois McMaster Bujold's Shards of Honor and supplied a copy (of Cordelia's Honor). When I wrote back & said I liked it & was interested in more, he sent all of the Vorkosigan books except one -- he stockpiles books for giving away. A revered mentor recommended N. T. Wright's How God Became King & I'm reading that now. I've certainly gone out and bought books after seeing comments by people here at Chrons.
Another of my profs, who died years ago, recommended various books, and one of them that I haven't yet read, Thomas Mann's The Transposed Heads, is on hand.
I'm never at a loss for something to read. I have hundreds of books on hand that are waiting for a first reading, and many more that I'd like to reread.