Information not on relavant man page - where to find on WEB?

[Richard Owlett <rowlett@cloud85.net>]

Man pages generally do not include information some users 
would find vital.

In fact
http://manpages.debian.net/cgi-bin/man.cgi?query=intro&sektion=1&apropos=0&manpath=Debian+6.0+squeeze&title=Introduction%20Section%201

explicitly states in part:
"... Man pages are terse, and allow  you to find quickly 
some forgotten detail.  For newcomers an  introductory text 
with more examples and explanations is useful."
and later states:
"A  lot  of  GNU/FSF  software  is provided with info files."

I often do not have available a functioning Linux system, 
thus my need for web based source of information.

My current problem is proper use of dpkg-scanpackages. I 
need examples of its typical and atypical use. I need those 
to give me the background for a sensible question.

Pointers please.
TIA