The achievement Higher Dimensional Learning involves hunting down books which spawn in set points occasionally.
This will show you the locations of the books you have not yet found.
Some of them are a pain to reach, requiring flight or jumping-items, and you might want to rely on the toy Beginner's Guide to Dimensional Rifting to teleport to them.
By default it'll only show today's book. This can be disabled if you want to see all of them.