From the time you arrive in the bay area you will start seeing the orange and black of the SF Giants...
You will have a wonderful time taking the ferry from Larkspur Landing which lets you off right in front of the stadium. And then get your peanuts and cracker jacks for the game! Or better yet, some Krispy Kreme donuts and a classic hot dog.
TIP: Be sure to dress warm.

http://sanfrancisco.giants.mlb.com/sf/ballpark/index.jsp