What testing tools, scanners and such, would be required to get anything out of the premium subscription videos and the book? Isn't the videos and the book fairly useless without expensive tools and scanners?
Oh not at all, there's a ton of value in the book and videos with basic tools! Certainly, you can do more advanced testing on a wider range of makes/models with the expensive toys, but they're not required for most issues.
Noah has a great thread going with suggestions for basic diagnostic tools below. Honestly, I use my test light and multimeter more often than anything else (besides the scanner), so those items would be the place to start.