The obvious ones - Royal Mile, castle etc are easily done on foot. Lots of steps in Edinburgh so things are close together generally but you'll feel your calf muscles in the mornings
It is a beautiful city so you can stroll about and enjoy it all.
We also did an open top bus tour which is good, some great vintage buses too if you are lucky.
For kids, Edinburgh dungeons is brilliant, don't miss that - you can close your eyes Steve
Lunch at Jimmy Chungs - a fabulous eat all you like Chinese, one of the best I've been to.