Unix for Mac OS X by Dave Taylor and Brian Jepson

Easy to understand. But I am quite sure that I will forget everything I've read in a month since I no longer work for a company with a server I may access, and I don't foresee myself printing, surfing, transferring files, or doing email from the terminal.

I only hope I remember these.

cd Go to your home directory
pwd Find your working directory.
/user absolute pathname
user relative pathname
../user backtracks one directory
ls list files
; command separator

And these too.

ftp something.org.sg
put filename
get filename
quit