Help Needed WIth Habermas

Hi guys, I'm expected to assist writing a paper on Habermas which basically means I need to fully understand and comprehend his arguments. I tried reading some of the primary text, but clearly Habermas's work lies on the more distilled and advanced end in the historical development of political theory. I can hardly claim expertise in every concept Habermas speaks of.

So I was wondering if anyone can sort of guide me on how I should approach this, and possibly suggest texts that I can use to develop a fairly decent understanding of Habermas, communicative rationality, and even post-metaphysics.