4-5 or so articles of his are available at t-nation.com though they might now be here, on site.
The title of probably three of them was something like high octane training.
I thought they were fantastic and still are. I’d love to see something like that in the future if and when time permits. I’d pay for such, actually-like the newest forum review?
Honestly, I think the best place to start is to let your friend read Speed Trap. It’s a surprisingly quick, easy read. I think once he gets through the first 10-20 pages he’ll be hooked and read the whole thing in a day or two.
The only other short introduction I can think of (which was actually my introduction to Charlie’s approach) is Joseph Horrigan’s article on Charlie that appeared in the June 1990 issue of Ironman. But I have no idea where or if you can find a copy.
I just checked Joe Horrigan’s website, and unfortunately it doesn’t have the article on Charlie, just Joe’s Sports Medicine articles (which are great in their own right).