Some Pre-requisite Topics To Review 

-- Flux, Luminosity, and the Magnitude Scale

-- Properties of stars 
     Mass, Surface Temperature, Luminosity
     Wien's Law,  Stefan-Boltzmann law
     Dependence of Main Sequence Luminosity on Radius and Temperature
    The Hertzsprung-Russell diagram 

-- MK Classification  of stars 
      Spectral type (OBAFGKM) of stars 
      Luminosity Class of stars
  
-- Lifetime of low and high mass stars  
     Principle of nuclear fusion 

-- Evolution and  End-phases  of low and high mass stars

On the class website, you can find some articles on the above material.