The book is fairly large and pink in color. The text of this book is in red.
Role in the episode
The title is about the customers of the Krusty Krab and the reasons why SpongeBob loves them, hence the name. SpongeBob and Squidward are the only sea creatures known to have read the book. It is known to contain the names of every person known to visit the Krusty Krab, excluding What Zit Tooya, although, SpongeBob probably added his name, upon finding it out. Considering it is hard to blindly match a name with a face, it most likely holds a picture or description of each customer. Many customers are not bothered by the disturbing nature of this book that contains all of their personal information because SpongeBob has never showed it to them yet.
This is the first book SpongeBob has written. The second is SpongeBob's Diary. The later book is actually published publicly.
The book says it is by SBSP, meaning SpongeBob SquarePants.