I cannot recommend enough Beej’s Guide To Network Programming. It makes an excellent read for those that who are just at the beginning of this vast and seemingly dry subject. I have been meddling with sockets for the past 2 weeks and my scouring on the internet for a good read lead me here. This is not a book that might be comprehensive, but it should lay a strong foundation for further development.
PS: The book itself is available online for free, but I urge anyone who can afford to support the author to buy the paperback. You will not regret it.