[adenadel]

I did a lot of auxiliary work when I was really competitive (mostly college), including weight lifting, sprint drills, dynamic stretching, hurdle drills. Generally, though, I usually just run (although this consists of a variety of running workouts). I never (literally never) do any static stretching beforehand.

In my experience, the most important thing is to make sure you build up the amount of running (quality and quantity) in a proper progression (don't do too much mileage or too much speedwork too fast).