Just a couple of suggestions.

1._ Don´t join one of these day tour operators. Last October we went to Karlovy Vary with one of them, and it was a bit of a disapointment, and too expensive.

2._ Public transport is very cheap. If you don´t want to fight with a czech-speaking clerk at the train station, go to the CEDOK agency in Na Prikope. They have come back to private hands after the Velvet Revolution, are nice, speak english and german, you can pay with credit card, and you can buy all kind of tickets (national bus and train, and international travel to places like Dresden, Vienna or Berlin). They gave us timetables to quite a few places, although we weren´t travelling.

We were in Prague for 10 days last October. Apart of the Karlovy Vary day trip, we went on our own to Karlstejn Castle (it deserves a visit, but check previously with the Prague Information Service to see if you can visit the Holy Rod Chapel, because it has a restricted amount of visitors in order to preserve it) and to Dresden. We wanted to go to Kutna Hora, but we decided to stay in Prague and enjoy the city.

Rgds from Covadonga in Bilbao