Be careful where you drink. My mates and I went out about midnight as we got there really late and all they wanted to do was stay in this one crappy bar rather then explore the area so I said i'd buy the next round if we went somewhere else. You hear about everywhere being 30p a pint etc so I thought i'd pulled off a good deal. Anyways my mates crazy friend dragged us into the Strip Joint that actually ended up being a brothel. We ordered 3 beers, and when they came they were cans the size of coke cans and it cost me £15 for the round lol! We just sat there in silence as we drank the beer as all the porzzies just stared at us... it was very uncomfortable lol!
Saying that we did find a few places that were only about 50-60p a pint and weren't full of prostitutes lol. Stay away from old town square as its really expensive, very picturesue tho so worth a wander around during the day.
Wenceless Square aint much to look at and isnt really a square... but there's a really really nice restuarant around there that is just on the left after you've left Wenceless Sqaure on your way towards Old Town Square. Dunno what its called but its down some steps in to a cellar and is all really chic but tasty and cheap.
The Charles Bridge is really cool and interesting, the castle is pretty expensive to go round and unless you have a guide it's pointless as all the info on cabinets and the walls isn't in English.
If you enjoy Prague i'd highly recommend Krakow in Poland as your next venture as although its not as picturesque I enjoyed it more and its a bit cheaper.