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.
"Would-be Sith Savage Opress has located his long-lost brother, Darth Maul! Now the two of them have embarked on a killing spree, cutting a deadly swath through the Outer Rim planets. Determined to stop the brothers, the Jedi Council sends a task force of skilled Jedi to hunt them down and bring them to justice. But when you’re hunting Sith, be careful . . . You might just catch them! Cover art by Dave Filoni, the supervising director of the TV show The Clone Wars!"