I am planning to go to Berlin and Pozan 10/2013. Maybe Warsaw. Which city should I start from? I will take the train. This will be my 2nd trip to Berlin. I did not see nearly enough the 1st time any suggestions for sites in those 3 cities?
Price out the airfare tickets to determine where to start - then see if open jaw ticket makes sense so you don't have to back track (flying into Berlin and out of Warsaw, for example). How much time do you have altogether, and how much do you need for Berlin? I can give you advice on Warsaw since I grew up there, but need to know how much time you have first.
Warsaw is pretty far from Poznan, whereas Wroclaw is much closer. We loved Wroclaw, pretty much a students' city but with plenty of German, Ukranian and Polish history (and the Austrians were there as well for some time). We also loved to see Görlitz, a city now divided into a German and a Polish half. You can pass from one side to the other just like crossing a state line in the US. The old town part on the German side is amazing. Also in the big cathedral overlooking the river, which is now the border between the two countries, there is one of the best copies of the Holy Grave - built in the 15th century.
@Andreas - but Poznan is more of a straight short between Berlin and Warsaw (and I'm guessing it's on the same rail line). Lodz is also on the way...I really liked it but some may find it a bit gritty (but that's what I liked about it) I agree though, Wroclaw is a great university town and good place to visit if you have the time.