I was trying to register an account for the wiki but this doesn't work. I only can see the login (which I can't obviously) and when I click on the create account link, I get an error saying that I'm not allowed to do that.
https://wiki.amigaos.net/wiki/Main_Page
Also I wonder if there is no documentation for the operating system functions, as I only found rather high level explanations but no details about the librarlies like exec.library, dos.library, etc. function calls.
I think you need to e-mail Steven Solie and ask him to create an account for you (you can find his e-mail address on his website).
The exec.library and utility.library are under Kernel:
https://wiki.amigaos.net/wiki/Kernel
Dos.library is under Libraries:
https://wiki.amigaos.net/wiki/Libraries
Also all of the autodoc files are also available in:
https://wiki.amigaos.net/wiki/Autodocs:Main