Tarkin follows the formative years of Tarkin, a master strategist and military commander. The book also follows his relationship with Sidious and Vader, and his rise to power. We see him work together with Vader to solve a complex problem and uncover a number of conspiracies.
I rate it a ‘must read,’ but I would definitely recommend reading Plagueis first, which incidentally is by the same author, and just as amazing.
The theme of the book and of its eponymous character’s life could be summed up well by a quote from one of its main characters, “Only glory can follow a man to the grave.”