I have Mimm's book, and I know it's a classic, but IMHO I think it's a bit too technical for beginners. That said, I first read it when I was in elementary school, but I still think it can easily go over your head. I've tried multiple times to restart reading it, and it was difficult to understand what was really going on after a couple of pages. Sorry if that gets a lot of people upset, I know it's like the holy grail of learning electronics.
I would suggest
Make: Electronics from Make:. It has gotten a lot of good attention and looks good for hobbyists and general beginners. Here's a blog of someone who's going through all the chapters:
http://handsonelectronics.blogspot.com/ I hope to buy it soon.
NOTE: Do you mean electronics specifically for FRC, like wiring the robot? In that case, you might want to look around at resources from other teams, maybe AndyMark, or even search on ChiefDelphi. I don't have any links to things like that, but for sure there are presentations out there that will explain to you how the electronics on an FRC robot work (components, basic wiring routes, etc.)
Hope that helps!