In the description of the book, it mentions the RichUI plug-in - which is for Grails itself - but does the book also cover plug-ins for Eclipse or NetBeans that make it easier to write Groovy/Grails apps?
SCJP, SCJD, SCEA 5 "The only rules that really matter are these: what a man can do and what a man can't do." Captain Jack Sparrow
Personally, I use IntelliJ, which was by far the best environment when I started with Grails, but with the release of Grails 1.1 I think the others are catching up. Check out the links above for more information.