Running is fantastic and addictive. If you are here because you want to run and aren't sure how fast and far to go without killing yourself and your newfound enthusiasm, you are in the right place. Almost anyone can run, you just need to put one foot in front of the other (sort of).
This part is kinda "duh, yeah Gregory!" but it needs to be said: if you haven't been athletic until now, you need to start slowly and build up. It's not just your endurance that you need to build up but your entire frame (joints, ligaments, etc). For those of you who are already active in a sport that involves running around (soccer) or jumping (basketball) then you are slightly ahead. If you have been playing golf, don't kid yourself. It's not an athletic sport; it's a past-time (insert flame wars in comments section, please).