Linux apropos command always returns "nothing appropriate"

Try executing 'makewhatis' as root. That updates the man page database, and creates it if it doesn't already exist, which it may not on a fresh installation.

'updatedb' updates the database for 'locate', and probably isn't related to this issue.

sudo mandb solved the problem for me. It regenerates the apropos database, but you have to make sure you run it with sudo.