Berlin has many excellent brew houses that are worth a visit during your stay.  These are not just a great place to grab a excellent beer, but also somewhere to find quality food at reasonble prices.

For example, try

Sophie'n Eck - 37 Grosse Hamburger Strasse

This small pub/cafe offers excellent food and a small but good range of beers from all over Germany including Kolsch, Alt and Pils.  The food is of a good standard and served thougout the day.  They also offer an English menu that will help you select the food to go with your beer.

Another great beer experience while in Berlin can be found at the house of 100 beers. It's in Charlottenburg on the famous Kudamm at Kurfürstendamm 100. If you're early, you might like their affordable breakfast fare, too.

You can also check out the annual Bierfestival Berlin in August, featuring over 200 breweries.

Also Berlin is home of a famous international brewing school (nowadays in cooperation with the TU Berlin), the VLB.