Get a public transport travel pass for the time that you are there, the buses, trams and metro are fantastic for getting around. Prague is a pretty compact city that you can walk around but after the third day walking up to the Castle/Charles bridge and it quickly loses its appeal.
Heres a good site for accomodation -
Mary's Prague Accommodation
Best club in Prague is Roxy (on Dlouha 33 ). Fun as f*ck and where the locals go to party and drink.
Don't expect service with a smile in a traditional pub, put a beermat in front of you and wait. Don't signal. A beer will either be brought to you or you will be asked which beer you want (light or dark, 10 degree or 12) It will be brought and dumped on your table, usually with a bang. This is not rude or surly, just how it is done. A piece of paper with a stroke on it will be put on your table. Don't lose it, or you will pay a big fine. You will be brought another and another until you ask to pay. Check the waiters math, they are often 'loose' in this respect, and then tip him a little extra (say the bill is 167 crowns - give him 180) Then you will get a smile. Service is slow and the staff usually spend half their shift chatting. Don't think this because of racism or ignorance - this is just the way it is. The locals get it worse, as they dont tip.
For eating out - avoid the tourist places, Irish/British bars and American restaurants. You will be paying the same price as at home. During lunchtime they have a "daily special" in most local bars and cafes. This is from the communist era when the government subsidised the workers lunches. You will get a bowl of brothy soup, a main of pork, dumplings, saurkraut(sp?) and gravy all for around 80 czk(4 dollars). Food is good, cheap and will fill you up for most of the day.
If going solo, learn a few Czech phrases beforehand. This is a good ice breaker. Prosim = please. Diky = thanks. Pivo = beer. Ahoj = hello.
English is taught in Czech highschools so most of the young people speak it. They are pretty damn friendly and if you go into a bar, it wont be long before you get chatting to some people. Its probably better to travel there by yourself as that way you will interact more with the locals.
A few tips on how to stay on their good side.
Be respectful.
-Don't laugh at how cheap everything is, or tell people that they earn a pittance for a wage.
-Be generous when you tip but not so much that it seems that money is no object.
-Don't p*ss in the streets.
-Don't freeload on the metro/trams. You will get caught.
-If you get an offer from some supermodel looking chick to join her in some bar just a five minute walk away - DONT GO- Its a scam.
-Carry an identity card. Its required that everyone carries some form of id.