Hal Macintosh predates the internet, predates Photoshop, predates MS Paint. This book shows the field before information was readily available, when the only way to learn how to carve was to watch carvers at contests. Many carvers in the field got their start from Hal's books, when this was the only source of written information about the field.
Learning to chainsaw carve using Hal's books alone is a total immersion process, wherein you are not sure how the parts you're seeing quite fit together until one day you carve something new and step back and say, "I didn't know I could do that!" Then you look at the pictures of other people's carvings and realize yours are just as good.
No chainsaw library is complete with only these books, but no library is complete without them, either.