If you are a teacher interested in the history of education, there is a great deal of material about the early years of textbook publishing (1450-1650) in Humanism for Sale.
At this point, you can find plenty of examples here, but if you want to go further you need to use the Table of Contents, look at my discussion, and then follow the links to the footnotes and bibliography. (323 KB PDF file) It is like working through a scholarly monograph in print.
Way too cumbersome! So I want to do better for you.
Eventually, I will offer a History of Education Contents, with links to translated documents and case studies. If you have specific suggestions for what should be included, I would be happy to hear from you. Some themes I am already considering:
Substituting print for manuscript books was the very first step in educational publishing.
Designing mnemonics (memory devices) into schoolbooks became common early on.
Printers started using type to clarify intended teaching methods.
The earliest teacher's editions with paired student editions appear in the mid-16th century.
How-to books become common about 1530, in many different fields.
Geography and Music have distinct trajectories for the development of textbooks.