What order should I read the series?
This question gets asked a lot… The real answer is that every single one of the Sword of Truth series books – along with everything Terry has and likely will ever write – is a complete story from start to finish. While each book [in the series] is part of a greater whole, you will always find a complete beginning, middle and end for each story.
There are characters introduced in Debt of Bones that will be unfamiliar if you decide to start with the prequel.
We recommend starting with Wizard's First Rule, then reading Debt of Bones to understand the origins of The Boundaries (an easy afternoon read), before picking back up with the second novel, Stone of Tears. Following that plan, all of the characters, places and characters will be familiar to you and you will get the „whole picture” better.
Source: http://www.terrygoodkind.com/books-00debtofbones.shtml