Having used the search function

I confirmed that the consensus is still what it was when I was more active here - that endurance athletes training several times a week (with alternating rest days in most cases, including this one) should only increase distance/mileage/time/etc by at most 5-10% per week. The numbers are more than reasonable - 10 miles one week, 11 the next, then 12.1, 13.3, and so on. However, what if the initial distance isn't a neat 10 miles?
I'm hoping to begin running and I want to do it the right way: smart, patient, safe and injury-free. What should I take as a starting distance? I could do .25mi runs this week, then .28mi runs the next, then .3mi runs... or maybe I should start at .5mi runs, or just .1mi runs. What do you think?
Relevant information
I haven't run regularly in 5 years (and since then I've gone through the majority of puberty)
My more short-term goal is to build up to 1mi runs, three times per week; these runs will be done on an uneven, grassy field
My long-term goal is to do 2-3mi runs three times per week; these runs will be done on paved sidewalks and occasionally concrete
My endurance is quite good, but only as a result of more low-impact activities such as cycling and swimming
I am 6'3", 180 lbs and lean
I overpronate as a result of extremely flat, flexible arches; although I have developed support muscles sufficient for cycling 60 miles at a time or walking distances, guiding the foot and ankle through a footstrike and pushoff is a totally different ballgame, and stride alone will take time for learning, strengthening and adapting
Let the learned answers begin!