My favorite work on the subject is Matthew Restall’s Seven Myths of the Spanish Conquest. It’s a perfect way for someone with knowledge of the basics of the conquests to be introduced to several wider historíographical developments that have challenged long held misinterpretations. For example, Restall criticizes the virtual absence of native allies in the narratives of conquest (while in reality the vast majority of warriors who besieged Tenochtitlán were not Spanish) and the assumption that the Spanish were successful because of some sort of vague cultural and linguistic superiority.