I already mentioned adding Unix-like help to Amiga DOS commands. Once again it's here: http://aminet.net/util/cli/Help.lha
Another very useful thing (especially if you are used to Unix or OS X) is Unix Commands for Amiga. They work great on Morhpos without any problem and the installation is trivial: http://jffabre.free.fr/amiga/unixcmds.html grep, sed, tail, wc... total of 23 commands