Dancing has always been a central part of Scottish social life. While the music to be played for dancing began to be printed in the 18th century, the first printed technical description of Scottish dance steps was Francis Peacock's Sketches Relative to the History and Theory, but more especially to the Practice of Dancing, printed in Aberdeen in 1805. Peacock gives the Gaelic names for the steps he describes, in a spelling that is all his own, but his book does not contain any illustrations.
Most dance manuals were published by dance teachers, who used their books to advertise their own classes. Donald Mackenzie's Illustrated Guide to the National Dances of Scotland (Stirling, [c.1910]) gives his own rates: 'three one hour lessons in Waltz, Military Two-Step, Scotch Reel Steps, &c., 10/6'.
Peacock Mackenzie's book comes with a fold-out guide to dancing a reel - by 1910, illustrations like this were easy and cheap to produce. You can see the full diagram here.