Start with Wage-Labour and Capital & Value, Price and Profit. These are two short pieces Marx wrote for working audiences rather than for scholars, and between them they lay out the core argument of Capital — commodities, labour power, surplus value — in about a hundred pages of plain prose. If the argument does not interest you here, it will not interest you across nine hundred pages.
Then understand what you are aiming at. Capital is three volumes, and only the first was finished and published by Marx himself; Engels assembled volumes two and three from notebooks after Marx died, and scholars still argue about how much of the result reflects Marx's settled view. The record on this path is volume one, which is the one people mean. Its opening chapter, on the commodity and the value form, is the single most abandoned stretch of text in political economy — dense, abstract, and written in a Hegelian idiom that arrives before any of the concrete material about factories and working hours that makes the rest of the book gripping.
The argument Marx is having
Capital is not a standalone treatise. It is a running critique of classical political economy, and its subtitle announces as much. The Wealth of Nations gives you Adam Smith on the division of labour and on value, and On the Principles of Political Economy and Taxation gives you David Ricardo, whose labour theory of value Marx takes over and turns against its authors. Neither needs to be read whole. Smith's first book and Ricardo's opening chapters are the parts Marx is actually working on, and reading the relevant hundred pages of each beats reading neither.
It is worth saying plainly that mainstream economics abandoned the labour theory of value in the late nineteenth century and has not returned to it, while Marxian economists dispute that this was a refutation rather than a change of subject. This is a genuine and unsettled disagreement. Reading Smith and Ricardo first at least lets you see where the fork is.
Getting the man in view
Peter Singer's Marx is the short introduction, roughly a long afternoon, and it is good on the philosophical inheritance from Hegel and Feuerbach that chapter one presupposes. Isaiah Berlin's Karl Marx is the biography, elegant and unsympathetic in places, and it situates the work in the political life. Neither is a substitute for the text; both stop you reading it as if it fell out of the sky.
Three companions that disagree
This is the part that makes the path worth following, and it needs stating openly: the three guides here read Capital in incompatible ways, and you should pick according to what you want.
Marx's Capital, by Ben Fine, is the compact and relatively neutral primer — the one to take if you want the argument's structure without a strong interpretive line. An introduction to the three volumes of Karl Marx's Capital, by Michael Heinrich, presents a value-form reading in which value is inherently monetary and social, and it explicitly rejects the view that Marx proved capitalism must collapse. A Companion to Marx's Capital, David Harvey's chapter-by-chapter transcript of the lecture course he taught for decades, reads the book as a theory of crisis and of capital's need to expand geographically. Reading Capital politically, by Harry Cleaver, is further out still: an autonomist reading that treats the text as an instrument of class struggle rather than a work of economics.
Harvey and Heinrich in particular contradict each other on central points. Do not try to reconcile them before you have read the primary text. Take one companion as your reading partner, finish volume one, and then read a second and enjoy the argument.
Reading volume one
Read the guide's chapter alongside each of Marx's chapters rather than in a block. Some readers, following Althusser, skip Part One entirely, begin at the chapter on the working day, and return to the value form at the end; this genuinely works and it genuinely loses the argument's foundation, so treat it as a rescue plan rather than a plan. The historical chapters on the factory and on so-called primitive accumulation are the most readable prose Marx wrote. If you want the other half of the quarrel, the Adam Smith on-ramp runs the same exercise from the opposite direction.
Follow the full ordered path here: What to Read Before Marx's Capital: The Preparation Sequence, in Order.
