Check out if there are any big match's etc before heading to the statium,as they lock it down some time before,there are loads of bunker,flak tower etc tours but they need to be booked in advance, day and week tickets on public transport are spot on and show our transport system up.
There is another huge soviet memorial in the old east that's in a park just a short walk away from the s rail route the name escape's me at the moment.there is still a lot of work going on and some musuems are closed or moved so any internet homework will pay off.
By the way the its a lot nicer going out at night there i'm just sorry the exchange rate is so pants at the moment.