Yay running!
Let's see:
a)start becoming fun - For me, about the time my short, easy runs were 3 miles.
b)starts becoming easier - well there will pretty much always be bad runs. For the most part it's "easy" for me now, unless I'm doing speed work
c)you start seeing results - what kind of results are you looking for? weight loss? increased speed or distance?
I run 3-4 times per week. 2 mid-week runs of 3 miles on the indoor track. Then on the weekends I do a long run and sometimes another short run of 3ish miles. This week my long run is a step back run of 5-6 miles, and next week my long run is 9 miles. I'm 6 weeks out from my first half marathon! Eek! My weekend runs are always outside. Races happen rain or shine, 30 degrees or 90 degrees, so I run in whatever conditions. There are a lot of greenways around here, so I just pick one that fits my mileage for the day.