Union hotel - tram stop right outside that went everywhere we wanted. Did exatcly what it said on the tin

Not right in the centre of town, so should be a bit cheaper, but close enough to be able to get places with no bother.
We didn't find anyone we couldn't speak to in English

Long weekend is prob about all you'll want.
There is a good nightclub right on the corner of charles bridge - huge place - 4/5 floors all with different music. There is even net access so you can send us live updates