I have ~9 days and plan on spending most of it in munich. I would like to travel to Nurnberg and Fussen and intend to use train/bus. I am dragging 2 teenagers along and want to see if there is an ideal way to plan the travel?
On travel days, get a Bayern Ticket. Unlimted travel in Bavaria for 22 euro on regional trains for the first person plus 4 euro per each additional passenger. Weekdays after 9 am, anytime on weekends.
http://www.bahn.com/i/view/USA/en/prices/germany-regional/bavaria-ticket.shtml
The 22€ price is for purchase at an automat. If you use a ticket counter (personal service), add 2€. If one of your teenagers is less than 15 yo, they would travel free on the Bayern-Ticket; the price would be 26€. If both are over 14, the ticket would cost 30€. Use the Bayern-Ticket for days you travel outside of the Munich metro district (all conveyances of the MVV are covered by the Bayern-Ticket). For travel inside the district, use day tickets (click on "Fares Day Tickets").