Now that I have tickets to Berlin booked, I'm in the process of researching the city and trying to figure out what's worth seeing.
Here's some links to tourism sites and blogs that are pretty helpful for planning a trip:
Visit Berlin - The official tourist website for the city
BVG.de - Tickets and fares for Berlin public transport. It looks like the weekly ticket is the way to go!
Berlin - David Lebovitz's tips for eating and drinking in the city, including the best places for currywurst
Berlin on a Platter - restaurant recommendations that make it clear that Berlin's a true multicultural city
iHeartBerlin - a guide to events happening in the city, including art, fashion, and entertainment
Mostly Berlin - a personal blog about the city