The 2001 Legends anthology, edited by Robert Silverberg, features a short story, "Debt of Bones," set a few decades before the events in the main series. Later the same year, it was published as a stand-alone novella.
Warning: Wikipedia contains spoilers.
The action primarily takes place in two continents, the New World (where the early books take place) and the much, much larger Old World (which is introduced in the later books). The New World consists of three regions; from west to east, they are the Westland, the Midlands, and D'Hara; they are separated from each other by barriers called the Boundary. At the beginning of the series, in contrast to the other two regions, the Westland is a region without any magic. The Midlands consists of many nations. D'Hara has always been ruled by the Rahls, the royal wizards of D'Hara.
In the series, the Sword of Truth is the magical weapon of the Seeker of Truth. The Sword of Truth has dual parts to its magic. It contains both the power of anger, hate, and rage, as well as the power of love. Only by using the magic of love will the Sword of Truth turn white. The Sword of Truth also "remembers" the skills of previous wielders, so that the currrent wielder can call upon the blade techniques used by earlier Seekers. In the time after a Seeker's death, before the next Seeker is found, wizards act as guardians of the Sword of Truth. Once a new Seeker is recognized, he will be given the Sword.
The current Seeker is the main character of the series, Richard Cypher. Other important characters include Kahlan, Zedd, Darken Rahl, and Emperor Jagang.