Before our cruise begins, we'll 1/2 - 3/4 of a day in Berlin. What do we need to see? What's the best way to spend our short visit? Also, any restaurant recommendations - esp. for lunch? Thank you!
Magdeburg...We arrive, have one night in Berlin and then we are off.
How are you getting from Berlin to Magdeburg? Is that arranged by the tour? From Berlin Hbf the regional train goes to Magdeburg. Too bad you don't have any time to spend there.. I spent a week-end in Magdeburg a few years back. True, you see those hideous Soviet style apt. buildings , these Mietskaserne The center is interesting, walk across the Elbe bridges.
I understand why you're asking your questions, but they are like saying "I have a half day in New York, where should I spent it and where should I eat during that time?" If you ask 50 different people, you will get 50 different answers - all valid.
So, my best advice to you is to get hold of a Berlin guidebook, and see what interests you the most. If your arrival will coincide with a walking tour, that's a great introduction: http://www.berlinwalks.de/public/. But just from looking at that page, you see the problem: Berlin has Nazi sights, Cold War sights, Jewish sights, gay sights, and much more, as well as enough museums for a few weeks. If you're not taking a walking tour, you'll have time for just one or two things, and will have to decide which one interests you the most.
Similarly for restaurants, if you want advice, you should tell us your desired cuisine(s), the neighborhood (or what sights you will be seeing before or after the meal), and a price range. On my last trip there in 2012, I had wraps, Turkish, Vietnamese, Italian, Singapore, and more - all reasonably priced.