This time of year, when I'm just getting back into a regular running routine, I run when there's no sun. I go after Allie goes to bed three nights a week, and on Saturday mornings, I'm up at four for my weekly long run. This early in the season that's only seven miles. My other three runs consist of two three mile runs and a five mile run. In September, I'll beef up my Saturday long run with a couple of nines and an eleven.
For the past six years, I've used Hal Higdon's training schedule. It's always been a good plan for me. I've learned that if you don't have a plan, you won't train properly and either won't finish the race or will get injured trying. But if you work your plan with discipline, you'll achieve your goal of finishing a marathon in a reasonable amount of time. I'm not saying it will be easy, but if you work the plan, you'll set proper expectations.