Matthew, I'm the runner that Isaiah mentioned...I've been to three different USATF Nationals, and I've placed in the top three in one event each time.
When I was twelve, I placed second in the 1500, and sixth in the 800, running 4:37 and 2:22 respectively.
You're training looks very good...for a 1500-3000 runner. Being a middle distance runner, it seems to me that you should shift the focus a bit more towards speed, especially as the summer season approaches.
Going from your current PR's to being a national champion in two events is a very ambitious and admirable goal, but I think that you should set some intermediate goals to help you along the way. Perhaps set the goal of making the finals at Nationals this year.
For this time of the year, you would do well to follow your current training, but I would begin doing one or two speed workouts every week or ten days.
Here is a couple of sample weeks of what I would have done during the summer season when I was your age:
Mon-1 mile warm up, 12x200 in 33 (goal 800 pace).
Do this workout in sets of 4, walking/jogging back across the field to the starting line for rest between 200's, and 3-5 minutes between sets.
Tue-Soccer practice.
Wed-1 mile warm up, 3x1 mile in 6:00..."comfortably hard". You should be pushing by the last interval. Take 5 minutes rest between. This workout is best done at a park, or somewhere where you can run on grass or dirt.
Thu-Soccer practice.
Fri-If you have a track meet Saturday, rest or do an easy run. If you're not racing on Saturday: 12x200m hill at goal mile race pace. Do this in sets of 4, or 6 if you can. Jog down the hill for recovery between intervals.(Slowly! The downhill running puts extra stress on your legs, so it's best to "shuffle" down the hill) Take 4-5 minutes between sets.
Sat-Track meet, or distance run (usually 4-5 miles for me)
Sun-Complete rest.
Mon- 1 mile warm up, 16x100m in 15-15.5 w/walk back recovery. 1/2 mile cool down.
Tue-Soccer practice
Wed-1 mile warm up, 6x300 in 46-47 w/full(7-9 minutes) recovery. 1/2 mile cooldown.
Thu-Soccer practice.
Fri-Rest.
Sat-Track meet. (1 mile warm up, racing any combination, or all of the 400, 800, 1500)
Sun-Off or 4-5 miles steady.
Isaiah might want to make a few corrections to those workouts, as my memory's a bit foggy...

I know that you're probably shaking your head at the idea of taking two days a week completely off from running to play soccer. But, let me assure you, that playing soccer, basketball, or any other such sport has many benefits:
1.Provides a mental and physical break from the repetitive pounding of running...basically protection from "burnout".
2.Develops aerobic ability, as well as speed, coordination, and overall fitness and strength, which prevents running-related injuries.
3.Provides a team atmosphere to balance the solitude of running and racing.
I've done very well in past years off of no base but 10-20 miles a week and soccer two or three times a week throughout the winter.
With the exception of the fast intervals, try and do as much of your running as possible on grass or dirt.
If you can find someone who is of your ability, or slightly faster, to train with, it will help tremendously.
I would also encourage you to keep a detailed log of the work you do...not only can it be used an effective training tool, it?s a lot of fun to look back and see what kind of workouts you were doing several years ago. I have a log of every workout I've done (save for a few weeks where I didn't record the info for one reason or another) since May of 2000.
Good luck.

Daniel LaCava
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Gonads and Strife...Weeeeeeeeeeeeeeeeee!
"The strong, the quick, the mentally sick. Runners. The fast, the sleek, the thin as a stick. Runners.
The speedy, the odd, the Saucony shod. Runners.
The runners, their peers, they're all snotrockateers. Runners. Runners."
Don't think...just be...be fast!
http://This message has been edited by prefontaine (edited 02-21-2002).