Need for a Thot tree

Hello,
I am have downloaded the Amaya for Windows 95/NT.
What is the significance of the *.S,*.P , *.STR.....etc.How do
I generate them? What is the significance of 'schemas'?
I wish to add FRAME support also.
How can I proceed?
Can I get some detailed documentation about the design issues of Amaya?
Thanking u in advance....
Joseph