Goals and How to Manage Them

So you've all heard this a million times: people need to have goals in order to feel like their life has a focus.
Like many other people my age, I have been a student nearly all of my conscious life. I entered preschool at 4, and I've been through elementary, middle, and high school. I went directly from high school to college. There were no gaps, therefore there was nothing to really have to think about. My life was set out and planned in front of me. My goals were set for me by teachers, professors, and parents.
Once I graduated, though, life changed a bit. I have some short term goals at work, but I find them mildly unsatisfying. I doubt I'm alone in this. Although I do enjoy my job, and I see its importance, I find it difficult to thrive entirely on the growth in my career for personal satisfaction.
That is why I am going to be taken on a new project, if you will. I have always dabbled in running, and in high school and college I found that it was a great stress reliever. I have continued to run since I've graduated, though I have had little structure in that portion of my life. This is where my discussion of goals comes in.
Currently I run about a 10 minute mile on an average day. I hope to shave time off of my mile over a period of time. Of course I have yet to clock my fastest mile. Once I do I can begin to figure out an appropriate time goal. I have quite a bit to figure out. But for now, I'm glad I have a goal!