There isn't a good book that covers WTP - the person who commented about
it being too soon was right in respect of WTP.
But if you want an overall book on Eclipse, I can recommend the Java
Developer's Guide to Eclipse, 2nd Edition by Jim D'Anjou, Scott
Fairbrother, Dan Kehn, John Kellerman, Pat McCarthy. I have no
relationship to these folks, and have nothing to gain, it's just a good
book.