ok....i'll give away a bit of a secret......go over the charles bridge, up the hill as if you are on the way up to the castle......near the top when you turn back on yourself, you'll find a place called the bazaar.
Go through the citadel like building to the roof terrace....you can see most of prague from there, and it is amazing.
Also, I don't know if has been hit by the recent flood, but myself and my partner ate at Kampa Park by the charles bridge. It was the most amazing experience of my life....do not miss out on either place.
Prague is heaven (and the beer is dirt cheap!)