This document outlines sources of product information for salespeople, including: 1. Formal training from the company or vendor. 2. Informal training from mentors, other salespeople, or vendor representatives. 3. Self-learning through observing others, reading materials, samples, videos, publications, manufacturer websites, coworkers, customers, and competitors. It emphasizes that product knowledge is important for salespeople to be able to explain how products meet customer needs and wants, especially for complicated or expensive products.