I try to walk as many places as possible throughout the day. I walk around my workplace instead of just making a call, I walk to work, I walk to stores and I walk my dogs!
When I hit my plateau, I signed up for the SparkPeople 5K running program. It involved 3 days per week of working up to jogging a 5K. It was a great program and I was incredibly excited to get to the end result! SparkPeople has a bunch of programs to try, so pick one and stick with it