We are planning to go to Nurnberg after we leave Prague and stay there for a couple of nights and then head to Salzburg for a few nights then to Munich. The more I plan, I am wondering if I should make Nurnberg a day trip from Munich to allow extra time in the Munich area and/or Salzburg.

Is Nurnberg good for a day trip from Munich or should we stay one or two nights there?

Thanks!

Nuremberg is not far away from the shortest itinerary from Prague to Munich.
Therefore it wouldn't make much sense to go directly from Prague to Munich and to backtrack from there to Nuremberg (and back!).
Salzburg could be a (1, 2 or 3) daytrip from Munich.

Use Czech Railways www.cd.cz - click More Options and Travel via and enter Cheb in the via box. Trains from €12 or €19 in 1st class. Nice rural run, good comfy trains.

Then use German Railways www.bahn.de/en for Nuremberg-Munich

The more I plan, I am wondering if I should make Nurnberg a day trip from Munich to allow extra time in the Munich area and/or Salzburg.

Tough call...there's so much to see and do in each place. We spent five nights in Nuremberg and never ran out of things to see and do. I spent four nights in Salzburg this past December and could have easily spent three or four more nights there too. Just depends on what you hope to see and do.

This totally depends on WHAT you are doing at each destination which is not stated. Each poster implicitly assumes a certain number of activities and make recommendations. They can be totally tangential to what you want to do. If you have tons of things to do in Nuremberg but not in Munich, your number of days allocation is totally inconsistent with your time allocation. But we don't know this.
When I help other plan a trip involving many of your destinations, I found that most people, at least he ones I have dealt with, tend to over allocate time in Salzburg and too little in Nuremberg. While Salzburg offer many venues, the touristiness of these venues seem to make people realize they might have allocated too much time. Of course, this totally depends on the interest of each individual.
I think you will come up with an itinerary consistent with you interest if you start from what you want to do at each destination, sort them in the order of importance. That should dictate how to divide the days needed at each destination.
Personally, I discount the days at a gateway city like Munich. Why do I do this? When I fly to Germany and back, the airport used are likely to be Frankfurt or Munich. This means, whether I like or not, I am "forced" to visit venues around Frankfurt or Munich at least on return leg of the trip. So I usually set "other" destinations as main and let Frankfurt and Munich pick up the remainder of days at the end to synch with the flight home especially when there is a significant price difference returning back on a certain day.

I like all three but you need more than a day at Nurmberg or you will be sad to leave.

We found Nurmberg very interesting. I recommend the city museum as an initial stop. I would subtract a day/night from Munich.

Thank you so much for this information! I must have been on a third-party site because the prices for those routes were SO much more. For Nuremburg - Salzburg, should I use bahn.de? As of now we are doing:
Prague - Nuremburg (cd.cz)
Nuremburg - Salzburg
Salzburg - Munich (I am assuming bahn.de for this one?)

I saw First Minute rates when I was looking - so much less expensive. Any pros/cons for this type of ticket? Also, for these train trips - do I need to reserve seats? Or will we be able to find 4 seats together? If we do the First Minute rates, we might just do 1st class because the difference isn't that much. Thoughts?

Thank you for your train help!

Thanks for all the feedback. I think I am going to keep it to 2 nights in Nuremburg as originally planned and I might adjust the time in Salzburg and Munich.