We run a Graphene chain called MELEK — same family as Steem — and we put all of our witness documentation up in public, free, no account needed. It is called Witness School:

Witness School — https://witness.melek.salon

It covers how a Graphene chain is actually built (the constants that define one — symbol, address prefix, the sha256 chain id, initminer, the witness set, inflation), how to build and register a witness node, the token standards, and a comparison of HIVE, STEEM, BLURT and MELEK on consensus, block time, downvotes, fees and the author/curator split.

If you already run a witness on Steem, most of it will be familiar — that is the point. It is written down so the next person does not have to work it out from source.