I decided to write this note after a fourth person asked me about my favorite book for winsock programming.
The answer is, since winsock is built on BSD sockets, and what isn't in BSD sockets but is in winsock is mostly Windows operating system related, your best bet is still the MSDN reference material. That is, if you already have some background in TCP/IP from Unix platform. If not, and you insist on a winsock specific book, there are not that many choices I know of. So this is probably your best bet.
If you are a beginning TCP/IP programmer, this will help. Pretty readable and well organized. But most of the examples in the book are for the type of applications which have already been written and rewritten several times over in the world and you can always find those someplace on the web. I find myself going to back to Richard Stevens volumes and to the RFCs, online documentations at Microsoft and elsewhere. But then, that might be because I started my TCP/IP days from UNIX/SunOS/IRIX.
For beginning TCP/IP programming this can be a good book. There are some paragraphs here and there with sloppy editing - technical and otherwise - but within tolerable limits. And, that is why I did not give it five stars.