We'll be using O'Reilly's "Linux Pocket Guide" files to play with.
man
ls
cd
pwd
cat
,head
,tail
vim
,nano
,emacs
mv
rm
cp
mkdir
wc
grep
diff
tar
,gzip
ssh
,scp
,nc
chmod
,chown
,chgrp
crontab
xxd
hexdump
gdb
python
binwalk
objdump
strings
file
md5sum
base64
...