Clarification:
What I described was the framework, but of course the specifics will vary depending on the individual, their race schedule and personal situation.
As was pointed out by another poster, you should not do the exact same workouts every week. There needs to be a variety and progression to your workouts. This can easily be done under the frame work given.
Whiel you may have 1 stamina, 1 speed and 1 long run each week (most weeks), they should not be the same stamina, speed, or long run workout each week.
Stamina workouts can and should vary between tempo runs, tempo intervals, long tempos (AT), short tempos (LT), progression tempos, tempos with alternations/waves, etc.
Speed workouts can and should vary working different speeds (mile to 10k pace), varying lengths, different recoveries, progressions made in speed/length/recovery, etc.
Long runs can and should vary from easy paced long runs to steady state long runs to fast finish long runs.
All of this done regularly while slowly building your mileage/frequency over the next several years. This variety and progressions coupled with increases in capacity/frequency will keep improvemenets and adaptation happening and progress will be made, allowing the OP to find out over time what their true potential is in the sport.
I have found the best way to make increases in capacity/frequency is to do it slowly and so the body has a chance to adapt and adjust to the new level and so that you have a chance to adapt your personal life and routines to it. By keeping the changes small and gradual significant increases can be made over time without it seeming too significant to the person. The body/person keeps slowly adjusting to the increased stress level and time demands.
A minimum of 6 weeks and usually closer to 26 weeks between changes in capacity/frequency are best. It is important to remember that sustainability/consistency must be maintained over the long term, so there is a real risk in pushing the envelope too quickly on building up your capacity/frequency.
It is when people try large increases at once or small ones too frequently where they begin to run into problems physically and mentally.
The OP is right in taking a long term approach that keeps his eye on the big picture.
Coach Mark Hadley
www.mprunning.com