Avarchy, no problem!
As for good hostels, there are quite a few. I left Vesta to go to another hostel recomended by another traveller called "the Clown and Bard" which was not bad and about 50 Kc cheaper. Of course that price was for the big dorm room with over 32 places for people to sleep. I was surpirised to see people sleeping in the rafters after waking up there. the staff is generally helpful but it is crowded and they have no lockers in the room.
I also heard very good things about Sir Tobey's, it is near a lot of public transportation. I am sure a couple members here would atest to the quality of this place, though I am sure it is more expensive (why I diddn't go there). Also Hostel Elf seemd nice.
But these are only the ones I have heard of or personally experienced. There are many others out there. I passed several signs for hostels but did not enter.
As for sights and bars... there are very easy to find
. Go exploring or go with other people- there is no lack of places to drink (I didn't go out in Prague for the drinking, honestly). There is also a club advertized as the largest in Middle Europe (I think, my memory is awful) with five dance floors next to Charles bridge, amongst others (I am not sure right now
). As for the sights, there is the old town, Prague castle (with a large gothic cathedral, Charles bridge, and well...I just walked everywhere, there are many sections of Prague worth a walk.
And so you will be prepared, I found the prostitutes to be the most aggresive there, so be prepared to walk fast and use your elbows!
I hope the weather will be good for you and a great stay in Prague!