The information will be easier to manage if we consolidate information based on audience.
An example plan:
Everything on the public website should be published with the expectation that it is public information, no access control needed. (Protected sites can be linked to)
A private system (wiki, etc.) with appropriate access controls would support giving access to parts of the system to particular groups:
Concerns have be expressed about ease of use for non-technical users - make sure a path to editing is available that all interested parties can comfortably use.
There should be a way to view a draft version for editing and comment before the documentation is published for use.
If documentation is to be placed on the web, it should support reasonable search and navigation (toc, breadcrumbs (path to document), appropriate use of HTML tags to support accessibility).
If documentation is to be printed, it should support page numbering, a table of contents, and good markings in the headers and footers.
Figures should be captioned for reference and clarity.
The private system should keep track of editing history (who made changes to a document, when they did it, and what changed).
Also useful is a system to track the age of documents in the system, and flag old documents for review (could be a tech task?)