I agree with those posters who recommend starting on the easern side. Roslyn Chapel is a must, for all sorts of reasons and it is within striking distance of Edinburgh, current home of the Stone of Scone.
If you have the time to get over to the west via Inverness, then try and visit Loch Ness, Skye, Glencoe on the way back down. The scenery over these parts is stunning and the battlefield at Culloden is one of the most eerie places I have been.
This link is a good site for info;