Japanese beer isn't German beer, but it's amazingly good. You can take anyone here even if they are under 20 (the legal drinking age in Japan) and have a free tour of the factory and the museum to find out how beer is made and what the history of beer is in Japan.
However, the real treasure is at the end of the tour, when you can have a half-hour tasting of ALL THE BEER YOU COULD EVER WANT. The tour is free, but if you're worried that everyone visiting Sapporo the day you are will also want to drink all the beer they can in 30 minutes, be sure to make a reservation. There is also a pretty famous beer garden inside the building that serves Genghis Khan, a local Hokkaido dish made with mutton that is so good you will never in your life think you'd associate the word "delicious" with the name "Genghis Khan."
Transportation: You can walk for about 25 minutes from Sapporo station or 15 minutes from Higashi-kuyakusho-mae station (Toho subway line). Or you can take the Loop 88 Factory Line bus from Odori station.