Hey there---I have run a marathon but I have only been cycling 3 months. Shoes--go to a running store
that will watch you run in several types of shoes before you buy--they will "fit" you according to your size and the way you run--also take your old running shoes if you have some--the professionals can tell from the way they are worn how you run. I did the USAfit training program--it is a six month traing program that takes you from nothing to 26.2 miles. It is a great program for training for long distance running. My goal is to do a bi-athelon (just the cycling and running). I can't do the swimming unless they let me use my noodle to stay afloat.
Bikechick B