Well I just took a look at a dummy day in Feb - one month from today and www.bahn.de/en lists several buses - clearly labeled with BUS in the remarks column - first one leaves at 7:15am - next 8:41; 10:41 and more throughout the day

19 euro fares were available a month out on most - full fare in 50 euros so book early to save. I used the link on the home page of www.budgeteuropetravel.com to get to the English schedule page of www.bahn.de so try that link and I'm sure you'll see exactly what I just saw. There are also trains that involve changing and take an hour or more longer than the bus - 3 h 37 mins. If you have a railpass it is fully valid on the bus so just need to reserve, always possible I think, not book early.

That's where you book the bus. The train does not travel on this route; only the bus. If you enter Nurnberg in origin and Prague (or Praha) in destination and click on the submit button you will see "bus" in the product column. Just continue to book your ticket.

Here's some further information to help you (I've taken this bus):

The bus is large and white and clearly labeled. It sits just outside the main door of the Nurnberg train station. You check your bags with the driver and he loads then underneath. There is only room for hand luggage on the bus.

There is a toilet and snack service but the best idea is to go into the station and buy some sandwiches and drinks to take on the bus. Once you get on if you don't like your seats you can change them if the bus is not full (unlikely that it will be full as it's large). The ticketing process automatically puts everyone in the front of the bus and the back will most likely be empty. I moved to the back to have 2 seats to myself; another person was in the back sleeping.

First class vs. second class ticket. First class is on the lower level; second class is on the upper level. I bought a second class ticket and sat up top. The seats were fine. I arrived at the same time as the first class passengers.

I've taken this bus twice - one trip there wasn't anybody in 1st class so I sat down there for a little while. The bathroom is downstairs, so I was down there for that anyway. 1st class was slightly nicer than 2nd, but unless I had mobility issues that would make going up the stairs to 2nd class an issue, I wouldn't pay the extra money.

I'd rather be up top in any case - seems you would be able to see better? I understand 1st being on lower level - more convenient boarding and by the toilets but this is one case with a first-class railpass as I often have I'd rather sit in 2nd class!

Pal - you can see better but there's not much to see from the bus. The highway with trees alongside it and the traffic getting into Prague. That's why I didn't mention anything about scenery from the top level.