A crucial text. This is my second time through it. I think Samir Amin is one of the most important thinkers to come out of the Arab world and this text is him at his best. My one recommendation is to be patient and stick through it. Once he gets to chapter 5 or so and onwards, the earlier reading is rewarded. To understand underdevelopment and the contradictions we're facing today (40+ years after the time of writing), you must understand the importance of the national question, the agrarian question, and its interrelation with class.
"The process of unequal development makes this question particularly acute in the development of class struggles. Thus it is important to distinguish between bourgeois and proletarian tendencies with regard to how the national question is posed and resolved.”