Last, here's a quick set I sent a buddy who's kid is doing his two years sabatical for church in Prague. It might help.
Okay, here's my short and sweet on Prague.
Prague is a small old city; in that the main tourist area is very compact, and the outlying area rather different. I only know the areas within a couple miles of the main (Wencelas) Bridge. That's the tourist area. Outside that you'll find a pretty normal city with good and bad areas, lot's of smaller stores and churches (and bars) than most people are used to in America. The city runs pretty normally, and a lot of the international government buildings are in the tourist zone. The work day runs from around 0700 to 1800. Don't make the mistake of expecting things to be open after that time unless you know the place specifically will. Usually only restaurants and bars are open after 1800. Most places close around 1300 on Saturdays and are not open Sundays. Even in the tourist areas.
Sundays are for church, and like many Eastern European countries they hold religion fairly close. After that they go home or sit outside in a plaza, depending on the weather. Saturdays are for friends. Sat night is the big night for "going out".
There's a fair number of ex patriots in Prague. Mostly British and Irish. There's a fair amount of crime, it's rumored to be a clearing house for Russian and Bosnian porn trade. You can get a book for free at the information centers on Expat life in Prague. It has everything you need to know if you're going to be there a while. If the Info center's out of them try a jazz bar called U Ceska Glena; just off Moskovia street. It's run by an American and serves great hamburgers.
Food. Anybody spending time in any European country knows that food near the tourist areas is expensive compared to "normal". The best exceptions to this are the open air markets; which do charge more in the city center, but have better stuff too. Make a practice of knowing where and when they are, and you'll always know where to get a good meal. ( I can find a market in most any major city, no problem. They never move.) The Czechs like spiced sausages, more potatoes than noodles or dumplings, and some veggies you may find strange (turnips, Brussels sprouts, etc). They also have a fair amount of Italian influence in the food, but it's done a little different. Fish is important, and so is lamb, but pork is the major meat source. Wild game is easy to find. Czechs make poor wine, top notch beer. Water is best if you use bottled. Expect to pay for everything; a packet of ketchup, a pat of butter, every piece of bread you take from the basket on the table, etc, everything.
Service in most places tends to the lousy. It's attitude, and you'll get used to it. Tip accordingly.
Tourist areas are crazy busy, and now over run with shops selling junk. Walking the area at night or on Sunday morning is much better as the crowds will be gone.
Road traffic can be bad, but it's not hard to get around on foot using the buses and trams. Bikes are good. Gas is expensive.
Prague still uses a lot of coal for power. You'll really notice this come the winter when it snows. Coal dust makes everything dirty.
Prague is a good looking town, and would be an even better tourist draw except it has a couple PR problems. It embraced the new Bohemian/Anarchist movement without realizing just how counterproductive it is. You'll find a lot of graffiti everywhere, and that costs the country money and jobs, so those protesting a lack of such things are shooting themselves in the foot. If Prague could get cleaned up like Salzburg it would increase business a lot. It also has a lot of "stag" visits (mainly from the UK) who are only there for the beer and girls, and are loud, drunk and rude. They're in Prague because the Dutch and Belgians have finally got tired of them and started making it too expensive to go to Copenhagen and other close sites.
I don't speak a lot of Czech, but still manage to get around. German is not as well received as English, especially by older citizens.
The exchange rate is a game, and you're going to get took. It happens to everyone. Get a local account and use the ATM.
Czech arts and crafts can be had a good prices, but not in the tourist areas. A smart person could work a couple bucks off ebay buying and selling. Glass and crystal are still very well thought of (among the best in the world).
Hunting and fishing gear are very expensive. 3-4 times USA costs. Clothes are not bad, but look different than what's in style in the US. This is good; get local clothes and speak a little language and you'll be accepted much faster. Get a local girl to help you and you'll fit in even faster. Get a student ID - there are big discounts for students.
Prague gets snow in the winter 3'-4'. Cobblestones are very slippery. They have good skiing but the Slovaks and Austrians have even better. Get waterproof boots; warm ones. It gets nice in the summer rarely up to 90.
There's all kinds of guidebooks out there, check Amazon, so I won't give you a lot of tourist stuff. The parks are great, take a lunch from the local stalls and go sit in the grass, that's what the locals do.