This is a small 137 page book which packs a lot of punch. It basically describes some of the more useful commands a System Administrator needs to know and how to invoke them over 5 different types of Unix.
As an experienced System Administrator it certainly taught me a few new tricks and would certainly be handy if I was faced with a Unix I hadn't used before.
It also probably had one of the clearest explanations of find I have read, certainly a lot clearer than most find man pages. This alone may justify its purchase.
This book would be good reference for a new user as well. It gives a broad overview of some of the more useful administration commands available. If they want more detail they can always read the man pages.
In conclusion I would certainly have this book handy if I was faced with a machine with AIX or HP-UX.