Phly, boy, phly
the weblog and site of Matthew Weier O'Phinney

Linux.com has had a running series on CLI commands for Newbies. Most of it has been very basic, but there are still a few gems within. For instance, today I was introduced to apropos and whatis. Give a search term to the former, and it will list all programs in which the search term is found in the manpages; give a program name to the latter, and it will tell you which man page addresses it.