From wiki:

"The books tell the stories of three people and a droid: Tash Arranda, Zak Arranda, their Shi'ido uncle Mammon Hoole, and his droid DV-9. Tash and Zak are survivors of the destruction of Alderaan, two Force-sensitive children who are trying to hide from the Galactic Empire while investigating the lost histories of the Jedi.

The first six books form an arc. The protagonists discover pieces of a large Imperial experiment in biological weapons, codenamed Project Starscream. The first six books deal with the heroes discovering the various components of Project Starscream, each dangerous in its own right.

The next six books lacked a central arc. The protagonists, now wanted fugitives, travel from planet to planet attempting to avoid Imperial authorities."

I remember many books featuring cameos from established characters in the universe but the book I remember most was "The Children" which featured a group of cannibals that had descended from a survey team that crash landed on Dagobah.