Handbook (noun)

1. A book of information or instruction about a particular subject or activity.
2. A small book that gives information on a particular subject.

Origin:

Handbook (n.) 1590s, from hand (n.) + book (n.).

Examples:

1. He was consulting a handbook on gardening.
2. She was reading a handbook on investing.
3. The company gave each employee a handbook on company policies.
4. The handbook is a comprehensive guide to the subject.
5. He was studying a handbook on photography.