The weekend before last was a long one in Germany which happily coincided with my birthday, and I had never been to Prague. That's really reason enough for me to want to go anywhere, so that was my present.
I went there in my favourite state of mind for traveling: not knowing anything about the place except: which languages will they likely speak there; what's the currency; is public transportation reliable; am I likely to get kidnapped for human trafficking.
It turns out Prague is a very hip place for tourists these days so almost everyone will speak English.
The official currency is the Czech Republic Koruna (25 CZK ~ 1 EUR) and you should definitely trade before you get there as you are very likely to be ripped off. There are as many people on the old town center asking if you want to trade currency as there are in Lisbon downtown asking if you want to buy drugs, so unless you are sure you know where to do that with a decent exchange rate in Prague or you can withdraw money with no absurd fees from your bank, take care of that beforehand.
You won't really need to use public transportation unless you intend to go outside the city center, since everything is in walking distance, or if you bring shoes which not so comfortable to walk all day in cobblestone streets.
And no, you are not likely to get kidnapped, or even robbed if you act like you would in any other European city.
With all that said, what about the actual trip? Prague is truly beautiful. If you have an inexplicable bias towards old majestic buildings, tiny cobblestone streets that form pretty mazes for you to get lost in exploring, gardens (actual gardens with flowers, not just parks, although they have those ones too), pretty little shops and a nice riverbank, you should go there. On top of that you'll even find great coffee and tea shops if you know where to look, and it was sunny and warm the whole weekend.
This map was a great help in finding hidden spots, but I highly recommend random walking and randomly getting in and out of trams. It's a great place for that.
Above: Staroměstské náměstí, the old town square. There was a street performer making giant soap bubbles.
Above: Us at Mama Coffee marking down everywhere we've been and enjoying their French press.
No idea. They light up at night.
There are more photos at the usual place.