These are just some resources on the GWT project. If I have time someday I might get back to this post to clear up some things.
http://code.google.com/webtoolkit/documentation/
http://www.onjava.com/pub/a/onjava/2006/05/31/working-with-google-web-toolkit.html?page=5
http://www.ibm.com/developerworks/opensource/library/os-ad-gwt1/
http://www.ibm.com/developerworks/java/library/os-ad-gwt2/
http://www.ibm.com/developerworks/library/os-ad-gwt3/
http://www.ibm.com/developerworks/java/library/os-ad-gwt4/
http://pcriddler.blogspot.com/2008/03/unable-to-find-myservicegwtxml-on-your.html