This is a book of variable value, the History lesson at the front was interesting. The chapters on spooling and Unix printing were excellent though in one or two places they seemed to skip ahead of themselves. The chapter on Samba was very good. Personally I skipped the Novell and Mac chapters, I have no experience of such systems
and can't personally comment on their relevance.
The chapters on LDAP and on SNMP can be useful if you read them a couple of times since the information in them isn't printed in a sequential manner.
Its short and readable. I read it from cover to cover in about 3 hours spread over a single week.
Some of the chapters such as accounting assume you can program in Perl (which I can't) C or Korn Script yes but not every system has Perl.
Even so there is a fair bit of good information in it and it is probably worth the price especially if you can get the company to pay for it.
It really needs some practical experience under your belt to get the most out of it.