BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
The Youtini Expanded Universe Ranking system is a 1-5 scale that ranks EU book quality, difficulty, and importance. Books closer to Level 1 are easier to read and understand, more important, and of higher quality.
A companion piece to the Journey to Star Wars: The Force Awakens character novels, Star Wars: Before the Awakening is an anthology book that focuses on the lives of Rey, Finn, and Poe before the events of Star Wars: The Force Awakens.