When I did mine I was 3 years removed from college running but had kept miles going just not workouts.
Average for the 24 weeks leading up to the race was 48.5mi.
One long run of 18mi @ 6:18 pace. Maybe 3 track workouts and a few to pace this fast girl who was training for the same race.
Mainly raced my way into shape...looking back it wasn't the best training I could have done.
Two half-marathons, 10miler , 5miler 2-5k's.
Best thing I did do was change my diet and drop down to the point where I was at my old racing weight. Weight is a big deal in the marathon.
2:36:12- At mile 4 the half-marathoners and two marathoners pulled away. After mile 5 I did the same. The pace had been too fast earlier. Ended up catching the guy in 2nd place by mile 24. Threw in 4 surges in the last two miles because I was imagining that guy creeping up on me....wasn't in my right mind.
Good Luck best advice I can give you is that no matter how good you feel stick with the pace you know you can hold. It always feels too easy for the first 8 miles or so.