i'm hesitant to say i'm some great expert because i bought Bob Schul's book, but I will tell you what I'm doing. I go to a town park right near my house, there are some nice trails in the woods and I run 3 miles nice and easy stretch some and get into the workoiy
it always starts with 10x100, I just kind of work into them, it's all on a large grass area i marked off with some approximate distances.
I usually do the first set of 160's, maybe 8-10. recovery is a little walk, I go again when my heart gets down to 130 or something
each set you jog a quarter, then run 8x100 with walk recovery
next set on tuesdays has more meat, 300-400's maybe a mile's worth, incomplete recovery
more jogging, more 8x100's
for me a third set is usually about it, on a harder day more 300-400's or on an easier 150-200's
i put the watch on the longer intervals
on the harder days it's 10 miles by the end so I just jog a little and call it a day, it's close to 2 hours, the other days are 8 miles at 1.45
I'm not very fast, so a better runner could cover more ground I assume.
My right foot is kind of messed up and all the left turns on the track are painful, so I can avoid them with these workouts.
my other runs are distance runs on grass or on the road and a weekly long run.
I'm not setting the world on fire, but I'm not hurt and I think my running form is getting better from really concentrating on running faster. All those 100's are real form builders.