My two books are independent. The NetBeans 5.5 book focuses primarily focuses on Java EE 5 technologies. If you're interested in Java EE and related tools (EJB 3, JPA, BPEL, WSDL, SOA, UML) then the NetBeans 5.5 book is still relevant, even for NetBeans 6 and 6.1.
The NetBeans 6 book focuses on rich client technologies (i loosely interpret this) such as Swing/GUI apps, NetBeans Platform apps, Visual Web & JSF web apps, Web Apps with JMaki, etc.
Adam Myatt<br /> <br /><a href="http://www.pronetbeans.com" target="_blank" rel="nofollow">http://www.pronetbeans.com</a><br /> <br />Author of : <br /> <br />Pro NetBeans IDE 5.5 Enterprise Edition<br /> <br />Pro NetBeans IDE 6 Rich Client Platform Edition