As someone currently living in the gray city of Aberdeen, I can't reccomend it as a great tourist destination, it is pretty much the same as Dundee or Stirling IMHO. On the plus side there are a few sessions about in the city.
Aberdeenshire however is a great place with lots of touristy stuff.
If you come in early July there is the Scone Game fair in Perthshire and the Stonehaven Folk Festival in Aberdeenshire. There are highland games most weekends, and lots of Farmers markets.
The Western Isles are lovely as it Speyside, lots of whisky distilleries!
It is a very nice place to visit!