Period, detail, and design.

The "big three" English furniture makers of the 18th century still have a strong influence on today's traditional style furniture.  The "big three" were Thomas Chippendale, Thomas Sheration and George Hepplewhite. Chippendale's publication was called The Gentleman and Cabinet-maker's Director. I find Chippendale's work interesting to look at from a historical perspective, but if you want learn how to identify furniture by period, detail, and design, a more readable modern text is "The Bulfinch Anatomy of Antique Furniture: An Illustrated Guide to Identifying Period, Detail, and Design".