Where can I find Mono documentation?
Why do I read “Documentation for this section has not yet been entered.” everywhere?
The mono documentation is just like the rest of mono very much based on the contribution of users. But unlike the actual code, documentation is not often contributed, therefore lots of the documentation is missing.
Where is the documentation for System.X.Y namespace?
You can find them on the .NET Framework API reference website.
How can I document my own code?
A good article on how to create documentation can be found under: Generating Documentation