From the ThinkGeek.com item description:
Sacred Myths is a series of 7 individual puzzles. Following the series sequentially, each puzzle contains clues and codes to solve that particular puzzle, as well as a password needed for additional hints for subsequent puzzles. It is possible to solve each puzzle individually, or solve them in order to take advantage of the hints. Up to you.
These puzzles can be pretty taxing. Solving them without using the hints makes them especially difficult. We were floored by the mechanism used the Carta Blanca puzzle box. It's one of the most unique puzzles we have ever seen. All of the Sacred Myths puzzles are hand crafted from solid wood.
The seventh puzzle will be released in the winter of 2009. Interesting. It could be a puzzle figuring out what the next puzzle will be!
Here is Thinkgeek.com's link for the Sacred Myths Legendary Puzzles.