Every Thursday the 'Hamburger Abendblatt' newspaper comes with an extra part that is called 'Live' - this lists all the concerts, movies, theatre plays etc. that are on at the moment. Easy to read. Comes with a calendar of events. Even if you cannot read the rest of the newspaper, it's worth buying.
It can prove useful to have a raincoat or umbrella around somewhere
Cycle! Bike paths are everywhere! Or maybe rollerblade? (click 'A short note in broken English' at the bottom of the rollerblade page...)
Do the Fishmarket on a Sunday morning only if you partied through the night before - it's too much stress getting up that early on a Sunday morning.
In Winter with absolutely bad weather around it can be worth considering taking the subway/ short bus ride to the airport. I've heard of Taxi's not making it in time :-)
Don't try to attempt driving on the left hand side of the road. All of Europe drives on the right. Only the Scottish, English, Welsh and Irish don't.