The discussion centers on recommended textbooks for learning Partial Differential Equations (PDEs) at the beginning-graduate level, particularly focusing on resources that cover Green's functions. Richard Haberman's "Elementary Partial Differential Equations & Boundary Value Problems" is highlighted as a standard introductory text. Other notable mentions include "Partial Differential Equations for Scientists and Engineers" by Stanley J. Farlow, which is described as informal yet accessible, and "A First Course in Partial Differential Equations with Complex Variables" by H. F. Weinberger, noted for being slightly more formal and comprehensive. Vladimir I. Arnold's "Lectures on Partial Differential Equations" is praised for its geometric insight and emphasis on physical intuition, making it suitable for self-study after a semester of ordinary differential equations. The discussion also references various Dover publications that provide valuable insights into PDEs and Green's functions, although some participants express a desire for free ebook options.