There's a cool store with only books by or related to Kafka, if you're interested in him at all. It's somewhere near the Old Town Square. Most people speak English as well as Czech in プラハ. As long as you learn please and thank you, you'll be fine (thank you isn't pronounced as it's spelled, by the way, so ask someone how to say it before attempting it or you may be really off).
Had a great time in プラハ, lots of sights to see and cheap food to eat - great!!
Go to プラハ before they go to the Euro (the Czech don't accept the euro yet) and prices sky rocket! It is a wonderful city with lots of old architecture, friendly locals, and great beer! Be warned though, Prague is super touristy (watch for all the old people in tour groups...grrrr). Go to the major sights (Prague Castle and Charles Bridge) in the morning to avoid crowds. Try eating at a place called U Provaznice (the Ropemaker's Wife) at 3 Provaznicka just outside the New town and try the goulash. Also try eating at a place called Klub Architektu at Betlemskenam 52, the food is AMAZING and a fancy dinner with drinks can cost you as little as 400 cK. Also have some drinks at Koznicka at 1 Kozi in the old town. Be warned though you can't use a Eurail pass in the Czech Republic.
Český Krumlov … All I can say is plan on staying longer than you expected when you get to Cesky Krumlov. Everyone does.
Český Krumlov … Cesky Krumlov is amazing. Make sure you go as soon as possible, before it truly becomes overrun by tourists and the prices double.
When you're going to プラハ, there's another town called Cesky Krumlov that you shouldn't miss. It's a historic town a few hours from Prague and a bus or train ticket is only a few dollars each way. And check out the hostels page for Cesky Krumlov on this site.