This page provides a top level view of information about treebanking in the DELPH-IN wiki.
If you have any guides not included here, please add them.
There are some language specific guides:
This is probably the closest thing we currently have to a general guide.
ErgTreebankingGuidelines although still very language specific
And some guides to tools:
Lexical Type Database descriptions of rules, lexical types and more can be found here