I originally learned Web Services concepts without books, so my opinions may be biased, but I don't think books would help much in the beginning. Once you get to some intermediate state where you need to study security, SOA, etc, maybe books would help.
I needed to get an intern up to speed on Web Services, so I made him implement a two-player game of Reversi using Web Services as the business logic layer with SQL Server underneath it. The UI layer was a desktop executable hitting the service.
You can do something like that using Axis2 and Swing. Once you've built the first UI, you can then try to consume the same service using .NET/Ruby/jQuery or something too to demonstrate the interoperability.