[HogunFan]

While you can read these books in chronological order, order of release date, by the mini series within etc... To be honest, it doesn't really matter, each book is so well written that each can be considered a stand alone book. While there are obviously connections between each book, you don't need to know what that connection is, or know any background to beable to enjoy the story.
I read Legend of Deathwalker first, and then read the rest of the Drenai series in a random order, depending on what the book store had in stock. And it made it, if anything, more enjoyable to pick up on the subtle connections between the books.