The battery in a 2009 Saturn Outlook is located under a floor panel behind the front passenger seat. To access it, you’ll need to slide the front passenger-side seat all the way forward and the back seat all the way back. Then, just pry up the floor panel and you’ll see the battery.
If you’re jumpstarting your Saturn, use the jumping terminals in the engine bay rather than a direct battery connection. If you’re replacing the battery, be sure to disconnect everything properly first.