How do I make default Championship files?

I've been messing with making some Championships for Race 07/GTR Evo. I set them up for myself, then copy the championship file out of MY directory into the Race 07 directory. Looking at other championship files I've downloaded, I've learned a little bit about what to delete and what to change, but I'd really like some more in-depth information about what I can/can't put in there and why.
For instance, how do I set a default race length and rule-set? How would I set up a multi-class...

How do I make default Championship files?