Now the achievement description itself is slightly confusing as it says to scan all of the books, however, there is only 1 that you have to get which this is located in the Mission called
"Train To Catch". Far along the level when you will enter a burning library you will have to run through a door way that is on fire, once through turn right, activate your TAC camera (
) and walk up to the book on the shelf, scan it (
) and you're done.
See my video guide below for a visual reference.