Being and Nothingness is one of the definitive texts of Existentialism. Unfortunately, it's also something of a cross between reading the dictionary and an instruction manual in Chinese in difficulty. This 12-part video series I made goes through Being and Nothingness systematically, chapter by chapter and either makes Sartre more accessible or just adds another layer of confusion. I can't decide which.
If Being and Nothingness is the gold-standard in Existentialism, Heidegger's Being and Time is... well, whatever is better than gold. Much of Sartre was a continuation of themes Heidegger outlined in his master treatise. In what will be another 12-part video series when I finish, I am breaking down Being and Time and extracting all the philosophical goodness I can.