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.
Note that a RESTful interface will probably be described with some example code and discussion rather than WSDL. WADL is the nominal DL of choice for REST but the big sites seem to just use example code.