Just got back from Edinburgh and we loved it so much we are seriously considering trying to move there someday! Haha.
We ate at Always Sunday, it's a breakfast and lunch cafe on the Royal Mile- delicious!! That was probably our favorite spot there. We also enjoyed treats at Chocolate Soup and we enjoyed the pub called The World's End (also on the Royal Mile). We ate at some other places that were just good, not fantastic.
Have a great time! We loved the castle, Holyrood house, the museum, walking the royal mile, visiting those monuments on the hill (can't remember what they were called). And make sure you get a picture by the fountain in the Prince's st gardens...so pretty! For those of you that do live there, I am totally jealous!
ETA- get fudge from the Fudge House on the Royal mile- sooo good especially their traditional butter tablet (the best out of all the fudge places we went to...and embarrassingly we went to a lot). We tried the Fudge Kitchen which is right nearby it, but it's not as good.