1.
model, example, exemplar
Something or someone that serves as a standard to be copied or imitated. Used for both physical models (such as calligraphy samples) and ideal behavior.
Writing
手 (hand) + 本 (book/origin). Originally referred to a copybook for practicing calligraphy or drawing.
Usage
Used both concretely (a physical model to copy from, as in calligraphy practice) and figuratively (a person or behavior to emulate). The phrase 手本を見せる means "to set an example" or "to demonstrate."
手本になる (to serve as a model) can be either positive or negative depending on context — it usually implies a positive model unless qualified otherwise.