I'm trying to read Das Kapital and doing a summary of it. It's good to do it after having some grasp of dialectics. If you observe the movement between concrete labor to abstract labor, abstract labor to exchange value, exchange value to money measurement of value, money measurement of value to price... These are all dialectical transformations and the result of multiple contradictions. Then you observe Das Kapital can be read as a onion, where you peel each layer before going to the next one.
Another one is "Introduction to the Modeling and Analysis of Complex Systems", from Hiroki Sayama. I'm trying to teach myself about complex systems analysis. And maybe use it to understand economics :-).