Legends of Shannara #1-2: Book Series by Terry Brooks
The 2-book set of mass market paperback novels includes the below titles:
Bearers of the Black Staff (ISBN 9780345484192): Five hundred years have passed since the devastating demon-led war tore apart the United States and nearly exterminated humankind. Those who escaped the carnage were led to sanctuary in an idyllic valley, its borders warded by powerful magic against the horrors beyond. But the cocoon of protective magic surrounding the valley has now vanished. When Sider Ament, the only surviving descendant of the Knights of the Word, detects unknown predators stalking the valley, he fears the worst. And when expert Trackers find two of their own gruesomely killed, there can be no doubt: The once safe haven has been made vulnerable to whatever still lurks in the outside wasteland. Together, Ament, the two young Trackers, and a daring Elf princess spearhead plans to defend their ancestral home. And in the thick of it all, the last wielder of the black staff and its awesome magic must find a successor to carry on the fight against the cresting new wave of evil.
The Measure of the Magic (ISBN 9780345484222): For five hundred years, the survivors of the Great Wars lived peacefully in a valley sanctuary shielded by powerful magic from the dangerous outside world. But the enchanted barriers have crumbled, and the threat of annihilation looms large once more. As he lay dying, Sider Ament, bearer of the last black staff and protector of the valley, gave stewardship of the powerful talisman to the young Tracker Panterra Qu. Now the newly anointed Knight of the Word must take up the battle against evil wherever it threatens: from without, where an army of bloodthirsty Trolls is massing for invasion; and from within, where the Elf king of Arborlon has been murdered, his daughter stands accused, and a heinous conspiracy is poised to subjugate the kingdom. But even these affairs will pale beside the most harrowing menace Panterra is destined to confront—a nameless, merciless agent of darkness on a relentless mission: to claim the last black staff . . . and the life of whoever wields it.