Here is a list of the set texts for National 5 and Higher English. Notable for their use of Scots are:

• Sailmaker by Alan Spence
• The Cheviot, the Stag and the Black, Black Oil by John McGrath
• The Slab Boys by John Byrne
• Tally's Blood by Anne Marie de Mambro
• Short Stories by Anne Donovan: All that Glisters, Away in a Manger, Dear Santa, Hieroglyphics
• Sunset Song by Lewis Grassic Gibbon
• Robert Burns: Holy Willie’s Prayer, Tam O’Shanter, To A Mouse, A Poet’s Welcome to his Love-Begotten Daughter, To a Louse, A Red, Red Rose

Resources

ClickView have resources for Sailmaker, Men Should Weep and Tally's Blood here. 

There are interactive learning games for Tally's Blood; Hieroglyphics and Burns poetry here. 

Below, a downloadable pdf containing a useful overview of Scots, guidance on teaching Scots language texts, and suggested texts for learners.