This is THE book to read on the problem of the transmission of antiquity -- it is written for the educated layman, yet is a book of scholarly authority. If one gets interested in the subject, the next thing is to find a copy of Lemerle's Byzantine Humanism -- published in French, but translated into (and publ. in) English by the Aussies --. The other thing to read is vol I of Pfeiffer's History of Classical Scholarship, which is a bit denser than Reynolds, however. (Vol. II was never written, and vol. III is not nearly as meaty).