Rail Question

If all you need is a couple of segments, a rail pass may not be economical. Rail passes are economical only for extensive use of the train. For just a few segments, individual tickets may be the best way to go. You will need to do that comparison yourself, based on the exact segments you need to travel.

To see pricing on rail passes, check here.
http://www.eurail.com/eurail-passes/select-pass

For pricing on individual tickets (and train timetables) you can go to the websites of the German rail company:
https://www.bahn.com/i/view/GBR/en/
Or the Austrian one:
http://www.oebb.at/en/

You can buy online ahead of time, if you want, and in that case special discounted fares may be available. However generally discounted fares have restrictions on your ability to get a refund in case of cancellation or you may have restrictions on your ability to change train departure, if you decide to leave on a different train at a different time/date. In other words if you buy a discounted ticket, you lock yourself into that specific train you book and you may be unable to change/get refunded (in some cases it may be possible but after paying penalty fees).

The main station names for the cities you mention are:
Munchen Hauptbahnhof (Hbf)
Salzburg Hauptbahnhof (Hbf)
Praha Hlavni Nadrazi (Hl.N)

No rail passes. There are less expensive options.

Quick question, will the 14 yr old still be 14 during the trip? 14 can get child tickets, but at 15 they are considered adults (for ticketing purposes).

Travel Munich to Salzburg on a Bayern ticket on Meridien trains for 28 EUR for the whole family if the 14 yo is still 14, otherwise it is 38 EUR.

Travel Salzburg to Vienna on Westbahn train, 25.50 EUR per adult and 1 EUR per child 6 to 14.

If you will just be taking local trains within Bavaria and to Salzburg and then 2 longer trips to Vienna and Prague, I don't think a railpass will be worth it for you.

Within Bavaria (including local trains to and from Salzburg), you can buy a Bayern Ticket, where up to five people can travel together. The first person pays €23 and each additional person costs €5. For families, one parent or grandparent pays €23 and up to 5 children are free. Any additional adults are €5 per person (up to 5 passengers total). You must travel after 9:30 a.m. Mon-Fri, anytime on weekends and you can only use local trains, not the high-speed ICE, RailJet or EuroCity trains. Tickets can be purchased locally at any train station.

Long distance trains to Prague and Vienna can be purchased online several months ahead for a cheaper price. See the German rail website for trains within or to/from Germany: www.bahn.com/i/view/USA/en/index.shtml or the Austrain Rail website for trains within Austria, or between Vienna and Prague: www.oebb.at/en/

Wtihin Austra, you can also take Westbahn trains between Salzburg and Vienna (and other Austrian cities), which always cost €25. 50, children under 15 are €1.

Yes, 14 and 11 are the ages they will be in 2017. Thanks for all the helpful advice, it is much appreciated!

As the others have noted, buying individual tickets will be your best option rather than a railpass. I just finished a 2-week trip through Bavaria and Austria and purchased local tickets for all my train trips.

For families, one parent or grandparent pays €23 and up to 5 children
are free. Any additional adults are €5 per person (up to 5 passengers
total).

For the Bayern-Ticket (and most other Länder-Tickets, including SW- and QdLTickets), one person using a 1-person Bayern-Ticket (for 23€) can bring along any number of their children or grandchildren under 15 ("up to and including 14") years of age for free. A maximum of one additional adult (could be the spouse or another child over 14 yo, but doesn't have to be related.) can also come along for 5€ more. Note: I believe without checking that some Länder (States) limit the number of under 15 children, but Bavaria is not one of them.

There are two applications for the Bayern-Ticket. One is up to 5 persons of any age. The other is for 1 or 2 adults and all of the children and/or grandchildren of one person up to and including 14 yo. The two versions cannot be combined, i.e., you cannot have three or more adults and all of one person's children.

Actually, children under 15, in most cases, are free although they usually have to be included on the ticket unless they are 5 yo or under. I just told you about Bayern-Tickets. For Saver Fare or full fare tickets, anywhere in Germany, just declare the under 15 chlld(ren) when purchasing the ticket (at a counter, automat, or online. They will be noted on the ticket but there will be no charge.

One Land, Hesse, allows up to 5 people on a Hessenticket. Up to three children, up to and including 5 yo, can also come along for free. Unlike most Länder, free children apparently do not affect the total number (5) of 6 and ups who can use the ticket.

You must travel after 9:30 a.m. Mon-Fri

It's been 9:00 for many years and still is, AFAIK.

Lee has provided a clear outline of the tricky set of rules governing passengers on the Bayern Ticket. It's very straightforward for meehan's family - but Lee's post should be helpful to more complex families and groups.