Very easy trophy.
Once you pick up the item titled "book", find a guard. Select the book, and place it either along a guards patrol route OR some place close by if the guard is stationary.
If the guard is on a route, he will find it as soon as it comes into his line of sight.
If the guard is stationary, you will need to get his attention. Knocking on a wall is great for getting a guard to your location.
The key is to be strategic - if you place one down and get the guards attention he will disregard it completely, and you will have wasted a decent distraction item.
Questions, corrections and neg vote justifications below.