The first book is a replica journal, like the earlier Equestria Girls Tell-All, this time from the eyes of Pinkie Pie in the MLP: The Movie universe. Besides the Mane 6 we also see Tempest Shadow on the cover, so she'll likely play an important role in this book.
The other book also features Tempest Shadow on the cover, together with Twilight Sparkle. This book is named "The prequel to My Little Pony The Movie", and is probably suitable to read before watching the movie, hence the release date of August 1st.
Below we have all information available regarding the two books, including links for pre-orders on Amazon: