I've been watching as much Scottish TV and movies that I can in preparation for my first RS tour and trip to Scotland. If you subscribe to Acorn TV, try the new Loch Ness mystery series. It's only 6 episodes; a new one is added each Monday. Wonderful scenery and a compelling story. Also on Acorn - a series from 20 years ago called Hamish MacBeth. MacBeth is the only constable in a small town. It's a quirky show, but also poignant in places.
Not on Acorn, but look for the movie Stone of Destiny from about 10 years ago. I found it in my local library. It's based on the true story of Scottish students who stole the Stone of Scone/Stone of Destiny from Westminster Abby in the 1950's in the name of Scottish nationalism.
Netflix has Shetland, another mystery series produced by BBC Scotland. This one is so good I've already watched all the episodes twice. Absolutely love actor Douglas Henshall in this!
I love the Scottish brogue and feel like I'll be able to understand it much better after watching all these shows.
If anyone has other suggestions for Scottish shows or films that aren't in the Rick Steves book, let me know!