Great strides have been made in galaxy evolution in the last decade through a combination of new and better observations, semi-analytic modeling of galaxy evolution, and simulations. Nevertheless, one of the biggest uncertainties has to do with how stars form on galactic scales. The role of "feedback," i.e. mass expulsion, the ubiquity of the IMF, star formation in the early universe, and how and how many stars form in particular galaxies are all open questions. In this context we will examine what determines how the star forming material, the dense molecular gas is formed in galaxies, and how this relates to the star formation within them. We will also review the first complete surveys of molecular clouds in nearby galaxies to see how the properties of the star forming material varies, and what this may mean for variations in the IMF.