I think your plan is pretty much in line with most runners. Run a bunch of races over the summer, have some fun, then start ramping up the mileage very slowly in the fall with an eye towards a spring marathon.
From a base building perspective you should set a date to start, (say Oct 1) lay down a week by week estimate and try to follow it up until Jan 1. If you miss a workout here and there no big deal. Come Jan 1 I would have a definite plan layed out for the final 3 months up to and including your taper and try to stick to it a little closer.
Lots of slow miles (8:30 pace) from the fall up to new years – get to where you can run 60-65 on singles with at least one mid week long run and then alternate weekends for the longer stuff. Like 14, 16, 14, 18, 14, 18, 14, 20, 14, 20, etc.
Be sure to work for 3 weeks then cut back for a week. I think you could stand to slow the paces down to ensure that you can run farther.
For the summer, set 1-3 races aside as one you really would like to do weel at and try to taper for them. Otherwise just have fun blasting whatever distances you come across.