First of all, here is the NetBeans.org web service tutorial section, which I usually recommend for people starting with web services, be it SOAP or RESTful:
http://netbeans.org/kb/trails/web.html Second, SOA is an architectural style which do not automatically imply the use of web services.
If you have not seen it, have a look at the Wikipedia article about SOA: http://en.wikipedia.org/wiki/Service-oriented_architecture You should be able to get some pointers from the article about different SOA-related topics.
Regretfully, I cannot recommend a good introductory book on the subject, since I haven't read any.
"Open Source SOA" is a nice book that discusses SOA development with Java, although it is more focused at Java technology than explaining SOA.