This is an important point. I have talked with too many good PC programmers who feel that networks are largely irrelevant to their work, and that network programming is some obscure skill, having nothing to do with the mainstream of programming. Not true on two counts.
Networks are indeed a vital part of the PC universe, and are becoming more important every day.
A recent survey of Fortune 1000 corporations, in fact, found that Novell had 56 percent of the installed base. The next largest company, IBM itself, had only 22 percent. What this means is, that if you're going to learn about only one LAN, NetWare is it. Fortunately, however, there are general principles involved in network programming. The other two concentrate instead on the nitty-gritty details of how to use the programmer's interfaces to particular PC networks.