Even though I am primarily a throws coach, I have still learned plenty about the runners and running in general. after all, even my throwers have to do a fair amount of running for their training. here are a few tips I have to keep yourself going strong. some have been mentioned already, so props to those who got em before i did here.
1. Warm-up and Cool down. at least 5 minutes of light intensity full body movement before and after your running. A moderately paced walk works well.
2. Stretching. Never stretch statically before you run. read: DO NOT STRETCH COLD MUSCLES. Some light ballistic/dynamic stretching is fine after you warm-up, but stretching should be done at the end of the workout. And I stress should as far as to practically say MUST be done. Stretching is very important if you want to keep your running days long and well numbered.
3. Heart Rate. Running in the real world is quite more difficult than running on an elliptical, or riding an exercise bike, etc. ceteris parabis of course. Careful that you don't just start right out into a 6 minute/mile pace and give yourself a heart attack/heat stroke or other nasty complication. Take it easy, and either monitor your heart rate with a mechanical device, or pay close attention to your rate of respiration. if you can talk easily, you can kick it up slightly. if conversation is impossible altogether, slow it down a bit. I wouldnt recommend going over 70% of your max heart rate until you have been running consistantly for a little while and are conditioned for it.
4. Footwear. Pay attention to what you run with. If you don't have a decent pair of running shoes (or walking shoes), pick up a pair. Even casual runners will need to buy a new pair of shoes once a year or so. But keep in mind you don't need to spend the big bucks on something real fancy.
5. Surfaces. Pay as much attention to what you run on. Not only for imperfections in the surface (cracks, ledges, slopes, etc), but also surface material and composition. Sidewalks of concrete are not forgiving and will wear out joints quite quickly. Hard tiling in schools and other public places is even worse (shinsplints are not all the fun they sound like, lol). Asphalt is more forgiving, but roads have a natural outward slope to them to help with water run-off. running on the same side of the road all the time creates an imbalance, and will cause injuries over the long term. Best bets: Newer treadmills that feature softer rebounds in their surfaces, tracks made of either all-weather rubber composite or stonedust (just dont trip up and fall down on those, it hurts even more than normal), and my personal favorite for my athletes: a nice grass field. generally speaking, green grass means well watered which means soft soil, and a far gentler impact than most other surfaces.
5. Environment. Check the weather. Really high temperatures, or high levels of humidity will negatively effect your body's ability to dissipate heat, which can be a real danger. Rain can make some surfaces slippery. Lightning kills too, lol. Dark, seedy looking alleys have thugs and murderers. Common sense works well here.
6. Form. Lastly, the way you run can severely impact your ability to keep running as much if not more than any of the other factors. If your weight shifts to the outer or inner ankle as you step, major issues await. consider changing your footwear, or even having a run clinic done. Avoid running on the toes (except when sprinting), and try to have a nice fluid transition from heel to toe on each step. Should feel somewhat like you are rolling your foot out on the ground. Avoid stomping, clomping or any other heavy pounding that results when you step flat footed. Try not to hunch forward, or lean backward when running. Use a nice gentle rhythm in the upper body, muscles relatively relaxed (also unless sprinting). Try to keep your neck in a fairly neutral position, looking around is fine, but careful that you don't have a tendency to stare at the ground or up in the sky by habit for the majority of your run. Keep the toes pointed forward as your step, some people are naturally chicken footed (toes outward) or pigeon toed (toes inward) when they step. Do what you can to correct this if at all possible.
Those are the most important things for becoming a consistant runner that I can think of right now. If I remember any others that warrant being here, Ill add them in.