Books for microeconomics and macroeconomics for selected topics
From Varian (7th edition):


Consumer behavior: at least chapters 1–6; preferably also chapters 7, 8, and 12.
Perfect competition and Theory of production: chapters 15, 16, and 18-23.
Monopoly price discrimination: chapter 25 (you might want to look at chapter 24; it seems a bit odd to study price discrimination without first looking at a non-discriminating monopolist).
Bertrand/Cournot duopoly: chapter 27.
Welfare economics is a bit tougher, because this could mean a number of things. I would suggest chapters 31 and 33 (and maybe chapters 32, 34 and 36).