Yes, I nearly mentioned the first book but reviews weren't that good as folks are saying it's outdated- 2003 is still a long time ago! Brushless motors are widely used now and I doubt they are mentioned much if at all?
Wouldn't hurt to get a copy though (I think I will) to give the basics and then look elsewhere for detailed and more upto-date information.
Brushless motors and electrics are probably the area that have changed most and for reference I can recommend an article on the Home page of Model Boats Magazine forum by the late, great, Dave Milbourn.
Edit: Having read the reviews again on Amazon as I've already gained some knowledge I'm not going to bother. Still think it best to target research and knowledge gathering based on what it is intended to build.