I loved the anime series, but was disappointed like many others when they cut it off early and never completed it the way it should have been. So these novels are the next best thing!
If you haven't watch the anime - I highly recommend the series. it is available commercially in the US, so i'm sure netflix or blockbuster have them for rentals. I bought my DVD box sets - so worth it! If you like the anime series you will want to read the novels too. the anime actually changed quite a bit, and added new characters - not is a bad way, but made it more commercial. Originals are usually always better.
The Twelve Kingdoms, Volume 1: Sea of Shadow
Is about Yoko's journey - unlike the anime, she enters the world of the twelve kingdoms alone. It is told entirely from her perspective and really shows her transformation from the meek student, into the hardened warrior. We learn as much about her inner battles with herself and just surviving as we do about the strange new world she is forced to cope with and understand.
The Twelve Kingdoms, Volume 2: Sea of Wind
This story follows Taiki's journey which was also covered in the anime. not only does he have to deal with a strange new world, but he isn't even human! Being raised as a human, he doesn't trust his natural instincts and being so young - isn't prepared for the responsibilities that everyone expects of him.
The Twelve Kingdoms, Volume 3: The Vast Spread of the Seas (coming March 10, 2009)
Judging from the cover - this look like it will follow the story of Enki and maybe Shoryu (King of En) which was also touched upon in the anime, but so much was probably left out.
There are 7 novels in all, *crosses fingers* that they all make it to an English translation!
If you love it, buy and support it! I do!! ^_^