I bought the American Crew Menswork three book, five DVD collection on a recommendation from Ivan Zoot. It is the best haircutting instruction I have ever seen. It is a system of teaching you how to see the geography of the head and then how to cut to the head form for different goals. The writing is superb for systematic consistency and clarity. The method moves you along as you develop understanding and get some practice in their techniques. The goals of techniques are well described in the text. The demonstration cuttings are all done by the same stylist. They are clear in the physical demonstration and in the commentary.
It does require studying and repetition. I am currently on my fifth go. In the first I made hand written notes on the text and demonstrations. The tools for cutting are shears, clippers with replaceable blades, and razor and they are all demonstrated repeatedly and with different goals. It will take me at least two more times of going through the text and DVDs and I expect these will continue to be good references for the foreseeable future. From the beginning, the lessons changed the way I planned and executed a haircut. Final form is becomming more predictable.
See http://haircutsformen.net/discussions/viewtopic.php?f=2&t=137 for several posts about American Crew. Some comments relate to the history of this company and I have no knowledge about this. Others point out that some of the haircuts are not things you will use much in a barbering situation. I have heard this type of objection addressed by others in two different situations which made sense to me. The most recent was by Don Haidl in the Sassoon ABC cutting course I took in Chicago. He pointed out that learning to do leading-edge styles was not so they could be repeated on inappropriate clients, but so they could be modified to fit the client for a suitable haircut. This makes sense to me. A similar explanation was made by a person who pointed out how the mohawk started out for a fringe group and has been modified to fit a larger part of the mainstream as a fauxhawk. Unfortunately I cannot recall this person's name.
I have not taken the classroom courses by American Crew. In the past, I have found that teachers always greatly improve the learning compared to just studying on my own. The information offered by teachers has frequently been the key for unifying the teachings in the text. I suspect the same benefit would come from the classroom work from American Crew.
I found the American Crew haircuts to be loaded with techniques which are applicable for either long or short hair on either men or wormen. In addition the analysis of headform topography is useful in cutting hair on women as well as men.
With the American Crew Menswork course and Ivan Zoot's clipper videos on YouTube there are lots of empowering techniques for cutting men's haircuts.