Yeah - the castle is pretty touristy!

At the start of a night out as a visitor it would be worth a trip to Oloroso. It is a very expensive restaurant but it is also a bar with a veranda opposite the castle. At night the view is special. Maybe have one or two there.

You can't really go wrong with George Street - the main drinking area (2 roads behind Princess st). There are lots of swanky pretentious bars there but also some good ones.

Avoid Tigerlily as it is the most expensive place in Edinburgh (then again - probably worth checking out for one). Le Monde is good and always vibrant and the is always the standing order (weatherspoons) for a cheap drink. CLubs round there - shanghai is good, Opal lounge is where all the rugby players etc go and why not is cheaper and cheesy. If you want some real dirty club but brilliant fun there is a place called garibaldis. It will be packed and vibrant. But its not up market!

Basically wondering around there, there are countless bars, pubs, restaurant on rose st (between prin and george) and up and down all the side streets.

The grass market is worth a vist too (under the castle). If you do that you can then head up to the George IV bridge where there are ample eat holes and bars including Bar Kohl which is an excellent bar for cocktails etc.

Down the road from there is the uni (potter row) again more bars etc but cheaper than in town.

If you feel like venturing around, wonder down the royal mile before/after seeing the castle as it is a good place to go and there are bound to be pippers busking.

Also there are open top tours from waverley station that go all over and you can jump on and off (ie in Leith docks, stockbridge etc) which covers loads of the city and is worthwhile if not a little cheesy.