Are there any books/articles/lecture notes on general networking theory that anyone can recommend? I want to learn network programming but want to understand at least the basic inner workings of networking first. Cheers

Most good general-purpose books about network APIs include a few chapters on the general workings of the networking protocols it supports. So a book on Winsock or Unix sockets will probably tell you what you need to know. Alternately, you might want to spend some time in a bookstore looking at books on networking certifications. An exam prep book for the CCNA, for example, should contain a good mix of high and low level details on network theory and practice.