Beginner runners biggest problem is that they run too far, too soon and develop shin splints or worse injuries which hamper they're motivation, and mileage. It always depends on the individual runner how far they should run when starting out. Someone accustomed to heavy leg training such as soccer players, basketball players, etc. are going to be able to run farther naturally than you're average couch potato. So here's the million dollar question, how far should you run as a beginner?
Well as said before, there are a lot of variations and factors to be included before determining how far one should run. Have they ever ran before? Have they ever exercised before? What sports do they play if any? Do you have proper running footwear which would cause excess mileage to damage they're lower legs. These are the types of questions you need to ask yourself before figuring out how much you should run.
A general rule of thumb for intermediate to advanced runners and for some beginners is to run based on how you feel. If you feel good after a mile, maybe do another mile, if you feel good after that, maybe try another half mile, etc. this also helps to know you're boundaries. However, most beginner runners do not know they're bodies limits and think they feel better than they actually are. Sure my shins are burning a little but I can do another 5k. Wrong, wrong, wrong. Only do as much as you can, distance building takes time. If you rush it, you're only hurting yourself in the long run. Better to take it slow now and be able to run rather than going to quickly and having to take time off sitting at home due to an injury.
The most common running schedule to follow as a beginner says that you should only run 2-3 times a week easy running at 1-2 miles per run. So for the average beginner that's around 15-30 minutes a day 3x a week with a day or two break in between each run. This may seem trivial and you may think you can do more but you need to listen to this or you'll burn out too fast. You're body needs time to adjust to the excess pounding and workload when adding on the miles.
So as a beginner, you should only be running 2-3x a week anywhere from 1-5 miles depending on your fitness level and sport experience etc. (Basketball and soccer players with stronger shins and leg muscles will be able to run longer distances when starting out obviously).