Free ebook - http://gocom.primeton.com/WicketDG/WicketDG00.php
Questions ask at mailing list - http://www.nabble.com/forum/Search.jtp?forum=13976&local=y&query=carfield

wicket jars respository - http://www.ibiblio.org/maven2/wicket/
wicket ajax example - http://www.wicket-library.com/wicket-examples/ajax
how to do stuff at wicket - http://www.mail-archive.com/wicket-commits@incubator.apache.org/msg00988.html
The model architecture - http://cwiki.apache.org/WICKET/working-with-wicket-models.html
javascript unit test and drag and drop - http://maven.codecrate.com/wicket-stuff/wicket-contrib-scriptaculous/
Main wiki - http://cwiki.apache.org/WICKET/index.html
wiki about iconverter - http://cwiki.apache.org/WICKET/using-custom-converters.html
repaint listview - http://cwiki.apache.org/confluence/display/WICKET/How+to+repaint+a+ListView+via+Ajax

Why wicket is good...
http://ptrthomas.wordpress.com/2007/03/02/wicket-impressions-moving-from-spring-mvc-webflow/
http://www.infoq.com/news/2006/12/wicket-vs-springmvc-and-jsf
http://evolutionarygoo.com/blog/?p=94

Frameworks comparison again, I think this one is short and to-point - http://kasparov.skife.org/blog/2007/08/07/