This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
HTTP is a more generic protocol which is the base (mostly) for the web and used to transfer the SOAP messages themselves. SOAP is a protocol to implement web services to allow interoperability. And WSDL is used to describe the web services and its functionality to the outside world. I suggest you read more about them in the official specifications (WDL, SOAP, HTTP)