This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori 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)