The Product Guide doesn't have much to go on, but the in-product help (click on the "?" in the specific section in the product) does explain each of the fields. The diversity of all the different options for every website make it very hard to have a very comprehensive guide.
It really depends on what you're trying to scan. Does your Website require you to log in? What sort of credentials do you need? FORM based, or NTLM etc. (configured in the Credentials / Web Application URL section)
Increasing the WebModule logging by adding the following registry tweak:
DWORD value "3"
Restart ScanEngine Service. Configure and scan... after the scan you will have additional logs:
They will show everything like the Request<>Response, and you can tell what our webmodule sends and what the website comes back with. This helps in debugging and might give you some clues, if you're still stumped and need some help configuring the scan, then it will be needed when you open a Service Request anyway.
I hope that helps!