@@Twila Starshimmer,
Umm... let me think... okay. Okay, I thought.
The first part of the book is about the world of Equestria and the Mane 6, then some other characters, and some concept art to go alongside. Following that is an interview with Lauren (the most informative part of the book and easily the best). Then are some... uh, other things... Please forgive the memory lapse... and then there are episode recaps with morals and song lyrics and quotes from the show's staff.
To actually fully answer the question, they were helpful to quickly look up an episode and its moral, but not much practical use, seeing as we can use the internet faster for such things.
I think that I would've liked something different there, if I wanted to nit-pick, but I'm not sure what exactly.