I have been following James for a number of years, and I learned quite a bit from his old training videos, which you can still watch for free on Youtube and on
www.thepokerbank.com. I have not read any of his books, but they would also not be high on my shopping list to be honest. The reason is, he basically stopped playing
online poker after Black Friday in 2011, and I feel, he has lost touch with, how online games play.
For microstakes cashgames I think, Crushing the Microstakes is a good place to start. Its a little outdated in some ways, but ironically COVID-19 has made it less outdated, since games are now more like, what they were 10 years ago. Which can also be said about James pre 2011 training videos.
For mid and high stakes games I think, the best training site is Upswing Poker, which is run by accomplished pros like Doug Polk and many others. Another alternative would be
www.pokercoaching.com, which is run by Jonathan Little and others. James by comparison never really made it to the top, so he is one of those guys, who tried to be a poker pro, and when it failed, he became a coach and writer instead.