list of programs in /usr/bin, /sbin, etc.
 

is there a site out there that provides a list (and details) of the commonly used programs located in /usr/bin, /usr/sbin, /sbin, etcl?

man pages, while helpful for these sort of programs, aren't really what i'm looking for. i'm looking for brief descriptions of what specific programs do (and if these descriptions garner interest, i will read the man pages if necessary).

i'd like to know what they do before i mess stuff up. :)

http://www.free-ed.net/fr03/lfc/030109/123/

Has a pretty good course on Linux, you need to go through their free and painless sign up, but it will have most of the info you want in it.