Ooh lucky!! I can't wait to get back to Scotland! I cried when we left after the wedding, even though we were heading off to Italy for the honeymoon - I would have gladly stayed in Scotland.
While at the castle, don't forget to look for the little cemetery for soldiers' dogs - it juts out from the side of the castle. It's so sweet.
You have to go looking for Greyfriar's Bobby and get a pic with the statue.
Rosslyn Chapel isn't far from Edinburgh and definitely worth a visit - the carvings are amazing.
I'm partial to Linlithgow Palace, birthplace of Mary, Queen of Scots, as it's the castle we were married in.
If you have time, I love Glasgow - the Necropolis is pretty neat, with all the old tombs and grave markers, and I found St Mungo Museum of Religious Life & Art fascinating, but I'm interested in different religions.
If you go to my website you can see the areas of Scotland we went to and it might give you some ideas. Just click on Britain 2007 on the right side menu:
www.shadowlark.com