Hi!
The Richard Monsoon Haefel book is actually a good introduction to
SOAP web services, regardless of whether you are aspiring for the SCDJWS.
Yes, it is slightly dated, but just skip the parts that are not relevant, such as those on JAX-RPC and UDDI.
It should be noted that the book is quite theoretical, so I personally combined it with a good does of practical programming exercises.
Best wishes!