Marcos
If you were really serious about wanting some Scottish history for the trip, then arguably the best place to start is (Sir) Tom Devine's The Scottish Nation: A Modern History (Penguin 2012). This is a properly meaty, brainy read with much to say about the current independence/union debates with which Scotland has been preoccupied over the past decade.
As for golf, likewise warm support for Jim Finegan's Blasted Heaths and Blessed Greens and (as ever on this site) if you can find a copy of Patric Dickinson's Round of Golf Courses and read the essays on St Andrews, Muirfield, North Berwick and Gleneagles, then you'll be enlightened in ways you were not quite expecting.
Enjoy...!