VaranisArano wrote: »If you are asking where you find lorebooks in the wild: https://en.uesp.net/wiki/Online:Eidetic_Memory
If you are asking about books in player housing: Once you have learned a set of books, you can purchase them as a furnishing from Mystics. You can also acquire books as furnishing from teh Crown Store, from a few other vendors, and from the Midyear Mayhem rewards (The Song of Pelinal books you mentioned). https://en.uesp.net/wiki/Online:Library_Furnishings/Literature