Microsoft gives you samples to use, but this will not necessarily teach you how to write an LSP.  Furthermore, you need to be absolutely certain that an LSP is your answer.  Winsock LSP is generally used when you want to change stream level communication. An LSP will receive the TCP stream completely assembled. To change or modify the stream at this level is very difficult, but can be done with LSP.  Komodia is the best resource when you are asking yourself, “How do I write a Layered Server Protocol?”

Chris