File system/directory structure docs?

["Marc Sherman" <msherman@myrealbox.com>]

I'd like to learn more about the anatomy of a debian
file system - what all the various [usr/[local/][s]bin
directories are for, where new apps I install (without
packages) should go, what /etc and /var are for, etc.
Is there a FAQ or HOWTO that I can read that covers 
this stuff?

More generally, what's a good strategy for finding the
approrpriate FAQs?  I've asked a few questions this week,
and all the answers were in FAQs or HOWTOs -- I just didn't
find them when I looked.  For example, I searched 
linuxdoc.org for "directory structure" for this question,
but didn't find much useful info.  Any suggestions are
welcome.

Thanks,
- Marc