A collection of writings of Marx, Engels and Lenin on anarchism and anarcho-syndicalism, published by Progress Publishers.
We do not agree with much of these texts but reproduce them for reference. It is worth bearing in mind that Marx and Engels had a particular axe to grind with regard to anarchism. Read this account of the split in the first international for more info. In terms of texts to read alongside, for Lenin we would recommend Gorter's open letter, Sylvia Pankhurst's open letter and Solidarity's excellent account of what he did once in power. For a general response to Marxist critiques of anarchism we recommend section H of the anarchist FAQ.