Not sure if this is what you need:
I do not really understand how you plan on actually measuring the miles that you do. I personally use a gps sport watch. In the webpage of this particular brand, you can log in your individual activities and you also have some social possibilities so it might do the trick for you. Of course the main problem is that you would need to buy the gps watch(es). The page I use is this one: http://connect.garmin.com/features
A less expensive option would be to track your runs with the gps in your mobile phone and use a free web such as this: http://www.endomondo.com/login Some friends of mine use it and say it is ok but I have no personal experience with it.
Finally, if you plan on running in marked courses and you want to upload the data manually, another alternative might be https://www.sportlyzer.com/ , although I am not sure on the social aspect on this one.