The discussion centers around recommendations for solid-state physics textbooks and lecture notes. Key suggestions include "Introduction to Solid State Physics" by Charles Kittel, which is widely recognized but noted for being vague compared to some lectures. "Solid State Physics" by Ashcroft and Mermin is also mentioned as a popular choice, though one participant has not yet tried it. Walter Harrison's series, particularly "Electronic Structure and Properties of Solids," is highlighted for its affordable price and comprehensive coverage of the Boltzmann transport equation. Additionally, "Elementary Solid State Physics: Principles and Applications" by Omar is praised for its clarity and depth, making it a preferred alternative to Kittel. The conversation reflects a strong desire for effective resources to enhance understanding in a challenging course.