Contract first development of web services means that you write the WSDL and associated XML schema by hand and then use, for instance, wsimport to generate code and additional artifacts.
An article describing contract first development can be found here: http://blogs.sun.com/arungupta/entry/totd_18_how_to_add Two books that dedicate at least a section to contract first development are:
Java Web Services Up and Running
Apache CXF Web Service Development
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com