Suggestions for Germany (Munich and Bavaria in general) and Salzburg, Austria

Hope you don't mind me making another thread but I finally settled on our plans after canceling our Baltic Cruise and deciding to do a land based tour in Europe. We will fly in to Munich on the afternoon of the 13th and fly back on the morning of the 22nd. That gives us 8 full days plus a good bit of the day on the 13th. We want to spend some time in Munich, 2 days in Kiefersfelden (brother-in-law is working from there this summer) and then head to Salzburg. Would love to hear any recommendations for these places or places nearby that should try and visit. I have always been a history buff so I can't even begin to figure out where to start, the options are just limitless. I've never visited Europe so being around so much history is very foreign to me.

So, please:

Must sees in Munich.
Must sees in Salzburg
Any other place nearby that we can do in a day trip that we must see.
Any tips on the rail system? I've been looking into it but it is a little confusing to me.

I know we won't have enough time to do everything but we can take the suggestions and make a list of what we will hit on this trip. My brother-in-law will probably be going back every year for a while so we can hopefully get back there another time to hit the things we miss.

We will be there July 13-21 (flying out on the 22nd early so I am not counting that) if dates matter.