IIRC as long as you walk briskly you burn the same number of calories by walking 5 miles as running the same amount. Of course, even a brisk walk will take you somewhere between an an hour and 15 minutes to an hour and a half to do whereas you could jog the same amount (theoretically) in half the time. That being said, 30-45 minutes of exercise 3 times or more a week is your goal, and if all you can do with "jogging" is job for 5 minutes and then double over, walking is a perfectly solid way to start out.
Personally, I walk around all over the place. I've been making a habit the past few weeks of walking from my house to a neighboring city around 7-8 miles away every weekend with my laptop slung over my back for, um, resistance. I also walk home from school every night I have a class, which is another 2-4 times per week. For me, it's a great time to listen to podcasts while doing something sort of exercise-y. I don't know whether you have that many free hours in a day to spend but if you do, sure, walking's good.