The best source is the internet and these forums. The electric side of the house is increasing exponentially and most books on the subject are outdated. Forums like this one are, in my opinion, far better than any book you can get. Just ask any question you may have and someone will be glad to help. This is an awesome community of folks who are always willing to help.
It's awesome you are getting back into it, especially with your Son. I started in this great hobby when my son was about the same age as yours. He made his first solo at the age of 9. He is 16 now and still an avid flyer. A bond we have made that I hope lasts a lifetime. Here is a pic of us from a few years back. He is taller than I am now!
Welcome to WattFlyer!