The chapter on the Web describes how to install a Web server (where to get the source from and how to compile it), how to configure it, maintain it, how to author material for it, what packages there are for producing usage statistics, how to use gateways to other services, and so forth. The sections on gopher, ftp and WAIS are similarly structured. In each case one particular implementation is described in depth (eg. NCSA httpd, wuarchive ftpd), but most of the material is general, and I think a good deal of it would be useful even with non-Unix implementations. It is assumed throughout that the reader has a solid knowledge of Unix and the basics of the internet.
The sections on the Web and ftp, the services I have had the most experience with, are very well done. I knew nothing about WAIS before reading Managing Internet Information Services, but it inspired me to create a WAIS index to my book reviews and a Web gateway to go with it; the explanation of how to do this was quite clear and saved me lots of time. I only read the introductory chapters on gopher, and I skipped the mailing list material completely, but I have no reason to suspect they are of lower quality.
While Managing Internet Information Services covers almost everything one could want, there are two things I would like to have seen included. One is a discussion of information management at an abstract level: to some extent general database and file-system issues can usefully be separated from the details of particular services. The other is some material on USENET. Not on running a news server (which is covered in another O'Reilly book), but on using USENET to provide information: how to work out what is appropriate for which newsgroups, why spamming is a bad idea, and how to advertise without upsetting lots of people. This could be coupled with advice on how to moderate a newsgroup and how to maintain FAQs and other regular information postings.
The "data librarians" in charge of services and the system administrators of the machines providing them are the obvious audience for Managing Internet Information Services. Ordinary users who maintain extensive on-line resources will also find it a cornucopia of useful information. Since it is these people who make the Internet what it is, and because Managing Internet Information Services should encourage others to join their ranks, I think it is one of the most important books on the Internet to appear for a long time.