If you need help with motivation to run, you're not alone. I have many ideas, but I'll just focus on five here:
1. Register for a race a couple of months away.
2. Make a running schedule. It's important to do this correctly. If you think you should just get out there and run several miles several days a week, think again. It will be much more interesting and exponentially more effective if you utilize the hard/easy/long run philosophy explained in my podcasts. Alternate hard and easy days and go about a third longer than your hard weekdays on one of the weekend days. Listen to my podcasts for very detailed explanation of this.
3. Make yourself a running calendar or just buy a calendar for the wall that has nice large boxes for each day, and write your mileage in big black marker on each day.
4. Total your weekly mileage and mark that on the calendar at the end of each week. Then, total the mileage for the month and put that in the corner with a ring of stars around it. This will make you feel great, that is if you keep up. If you don't, it is punishment. It will make you feel like a slug, and you will do better the next month because no one wants to feel like a slug.
5. Buy some cool new running shoes. You'll be aching to run :)