The wikia is a great source for information on the game so see below for details.
These are the clans that you are allowed to play:
Schools from the following books are allowed subject to my say so. Although no Ninjas, Monks or Ronin.
- Core Book
- Book of Air
- Book of Water
- Book of Fire
- Book of Earth
- Book of Void
- The Great Clans
- Imperial Histories 2
- Strongholds of the Empire
- Secrets of the Empire
For a nice list of schools by clan you can also look here or you can check the media library as I have uploaded a few word documents which cover most of the things you'll need to know.
There is a nice character creation tool found here. If you want to use that to get used to how characters work. Character creation itself will be done on the first session, any questions while thinking about your character feel free to ask and I'll answer them.