Currently, we have available for your enrichment:
Assembly Tutorial (draft) (Last Update: May 13 2002)
Syscall Reference (Last Update: May 26 2002)
Kernel Design Notes (Last Update: May 26 2002)

Some documentation is also provided in the source release. The code is changing much faster than the documents can keep up with, sadly, so it is vital you subscribe to the Argante mailing list (see contributors section for details), where the development team will either cheerfully and courteously answer your questions, or get frustrated enough to create a FAQ and update the docs.