"Marx's Concept of Man" is essentially a pamphlet establishing the humanist, philosophical side of Marx as against the orthodox, Soviet view of Marx as tyrannical and economistic, and against the degree to which this view has seeped into academic literature in the West also. Famous Freudian Marxist Erich Fromm uses the "Economic and Philosophical Manuscripts" as well as "The German Ideology" to stress the importance of humanist concepts such as alienation, freedom, and creativity for Marx, and in so doing explains what these and similar terms mean in Marx' work. Fromm has clearly paid careful attention to Marx' philosophy, and this part of the book is quite good as a simple overview.
The second half of the book covers the English translation of the aforementioned "Economic and Philosophical Manuscripts" by Tom Bottomore, as well as excerpts from various other works by and about Marx meaning to show his humanism, his good nature, and his sensitivity to culture. Of special interest are the excerpts from the memoirs of those who knew Marx, like his daughter Eleanor as well as Paul Lafargue. These works are often quoted, but rarely does one find a larger part in English, not even in McLellan's biography.
Fromm goes a bit overboard here and there in stressing Marx' 'spiritual' nature. Although nothing Fromm writes is of itself incorrect, it may unwittingly reinforce the old canard of Marxism 'really' being a religion, and Marx a millennarian prophet, and so on. Fromm obviously rejects this old refrain, but should have made that clearer. In other aspects this collection is an interesting primer on Marx as thinker on human action and human nature, and sheds good light on this side of Marxist thought for those not familiar with it.