If you enjoy a challenge, a pedometer can be a great tool. You can try to walk more tomorrow than you did today. Or more in September than you did in August.
Some folks just wear one for a few days (doing their normal routine) and then just work to increase their daily steps.
You can buy them as plain or fancy as you wish. Some have mileage counters, some just track steps. Leenie is right, they all come with instructions.
When my family doc was thinking that my heart rate was too fast and my blood pressure was rising, he suggested 20 minutes to start. I used to drive with the car odometer to see how far I'd gone