Man i did a eurotrip last year, and i can tell you a bit about Prague- considering i used to live there.
Get your beer from the supermarkets- 6 crowns for half a litre (and last time i check 1 Euro got you 30).
Food to get- national dish is vepro/knedlo/zelo (pork, dumplings and sauerkraut), but the best thing you can try is a special steak dish called Svickova- basically a steak in a special vegetable cream sauce. The steak is traditionally drowned in suace and when its done the sauce is eaten by itself because it just tastes so good.
Touristy things to see: Charles Bridge, Old Town Square and the Prague Castle are the obvious ones, but take a few trips out of town if you can. Karlstejn and Konopiste are both amazing castles, jsut day trips out. The towns of Cesky Krumlov and Karlovy Vary are just too good to miss out.
Nightlife: Msot popular places are Karlovy Lazne and Roxy. Karlovy Lazne is just next to Charles Bridge and has 5 different dancefloors. Its a hell of a fun night out, but many locals avoid it due to its reputation as a drug hub. About half the people there are travelers like yourself. Roxy is an old cinema complex off Dlouha Trida (best accessed by the tram stop of the same name). That place attracts more of a local crowd, mostly hippies and alternative raver freaks. Great if you like electro and wading through clouds of pot smoke.
As far as girls go, czech girls are incredible. They are my absolute favourite species of girl in the universe. The best- and most beautiful- girlfriends, flings and one-nighters i have ever had have been czech girls.
The best tip you have of scoring with them is to LEARN CZECH!
Im fluent in the language so i had no shortage of dates there, but learning a whole language in a month is a tough ask so jsut try what you can. Any attempt to learn the language and use it will be greatly appreciated.
Youll find that in Europe a lot of people will be a bit intimidated by your english (but will still want to talk to you- to practice) and apologize for how bad they are. Not this is not applicable to all places. The more a place is saturated by tourists the more likely your prescence is to be annoying, and seen only as economic fuel. The lest touristy a place is the more likely you are to be seen as something exotic
The best thing you can possibly do when visiting any of these countries is to MAKE AN EFFORT TO LEARN A BIT OF THEIR LANGUAGE AND BE RESPECTFUL OF THEIR CUSTOMS. Act like some drongo hooligan and you have no chance my friend. Locals will warm to you instantly if you do the above.
Other random things I know/have noticed:
Europeans are much more comfortable about sex (but that doesnt nessecarily mean their easier to get in the sack)
European girls are much more feminine than their American/Aussie counterarts. They are quite happy to let a man take charge and more often than not expect it from him
European girls look more for a man with substance, and are less impressed by bling. The further east you go the more applicable it gets.
Paradoxically the further east you go the more money is a turn on. Women will want you jsut for your passport and exchange rate (the more impoverished a nation/region is the more this is applicable- think Ukraine)
Some Eastern European women will do anything to escape their own countries (hence mail-order brides).
Have a good trip