1998 Saturn please help (batter.I think)

Other Category problem
1998 Saturn 4 cyl Wheel Drive Type unknown Automatic 54,000 miles

I have a '98 saturn station wagon. If I do not start it everyday I have to jump it before it will start again. Also whenI am at a stop light it has a tendency to want to power off (w/ dimming lights) unless I put it in N and rev it a little bit. This also sometimes happens when I first start it. Can you help? Do you think I need a new battery?