Hi,
This was already covered in another topic here (sorry I can't quickly point you to it) -- basically, the new handbook for 2006 isn't ready yet, and seems to be taking a little longer than expected.
In the absence of any "news" when the new handbook's available, if you mouse-over just the Handbook on the downloads page it should show you the file name, which will include "2006" when the new one's available.
Best,
Mike