Today I passed the SCDJWS-exam (310-230) with 95%.
The last 10 weeks I spent a lot of time (about 8 hours a Day and more) on preparing for the exam.
Material I used:
SCDJWS Study Notes by Ivan A Krizsan
Service-orientierte Architekturen mit Web Services by Ingo Melzer (a german book)
Java & XML for Dummies by Barry Burd
XML Schema by Marco Skuschus and Marcus Wiederstein (a germon book)
WSDL tuturial on w3schools
Documentations on Sun's official sites
Followed the online course at javapassion
Read many threads at javaranch and hundreds of other sites in the world wide web
Helpfull are discussion with an colleague of mine, who has already experince about Web services.
So I felt well informed and the exam wasn't as difficult as I expected.