i have been there two times last year.
If you look for an accomodation i suggest the Mary's agency (
http://www.marys.cz/); i used both time and it was ok.
About the pubs i suggest U Pinkasu near the wenceslav square (it's in the Mike's link); U Fleku and U Kocouro are more touristics but i think they worth a visit. Anyway the beer, IMO, it's great and pretty cheap.
As a restaurant i suggest U Proznovice, great and pretty cheap food for the center of Prague; it' on the first road on the right going from wenceslav square to Malostranke. Another one is the Hotel Diana (the boss of the Czech company with who i worked suggest it to me) but it's outside the centre (Prague 9).
For the shag, as Mike said, it's pretty expensive but you can find some information at
http://www.escort.cz.
If you need more information ask me.