Helm

Sometimes trashy sci-fi can be the best kind of fun. Helm is a fun, cool, fast-paced adventure story. Here's the book's description (snagged from the back cover):

“After global devastation, the last remnants of Earth sent a handful of colonists of a distant terraformed world to give humanity one last, desperate chance. Unable to provide the technology required for an advanced civilization, the founders instilled in the colonists a strict code of conduct and gave them a few precious imprinting devices: glass helmets that contain all of Earth's scientific knowledge.

Once in a generation, the heir to the province of Laal begins the arduous training required to survive the imprinting of the Glass Helm and acquire the knowledge of the lost Earth. But Leland de Laal, the youngest son of one of Agatsu's greatest leaders, has climbed the forbidden rock spire where the Helm is kept and donned it, unaware that its knowledge has a terrible price. To an unprepared mind, it brings madness, agony, and even death.”

One of the coolest consequences of Leland's premature imprinting is that he's picked up knowledge of aikido. With further training he hones his martial arts skill and the fighting in the story is filled with slick descriptions of it. This story is filled with chases, battles, double-crossing, betrayal, dark dealings, and many fights with sword, staff, and arrow. Although set in the far-future, Agatsu's society is medieval. Makes for a very fun tale.