Here is what I would do, assuming your summer is about 12 weeks:
Wk1 - 30 miles
Wk2 - 35 miles
Wk3 - 40 miles
Wk4 - 35 miles
Wk5 - 40 miles
Wk6 - 45 miles
Wk7 - 50 miles
Wk8 - 50 miles
Wk9 - 45 miles
Wk 10 - 50 miles
Wk 11 - 55 miles
Wk 12 - 60 miles
That is a lot slower build up than SoM suggests I believe but if you are injury prone you need to build up slowly and cautiously.
As far as the break down:
Wk 1 - 4 just distance work, no speed, no hard effort just solid getting in the miles and building your miles up.
Wk 5,6,7 I would through in one good hard tempo run/week, probably starting out with a 3 mile tempo week 5, and adding a mile each week.
Wk 8 no tempo
Wk 9,10,11,12 5 mile tempos each week + an additional interval type workout each week (16X200, or 400s or 800s) with very short recovery and a medium effort just to maintain some speed.
I'd do a long run every week past week 4.
As far as doubles go, since this is your first time doing doubles (I assume) start at real slow and easy. I know malmo would disagree and thats fine, but what I would do is add a double a week starting around week 3, until I was doing 4 doubles a week. Personally I think if you are doing more than 4 doubles a week in high school you are really pushing it and getting significant deterioration on your return on investment, especially with it being your first year and all, (I would actually suggest 3).
The biggest thing will be staying injury free, run on grass or dirt as much as absolutely possible, which should be every single run. I don't think there is a place in this country where you can not find a decent soft surface to run on. Stretch well and make sure your shoes are good to go (as an aside I too had injury problems in high school, consistently, until I switched to a light weight shoe, pretty much a racing flat and that made all the difference, but again I was running on soft surfaces).
You are going to be tired coming into the cross season most likely, and your first few races could be poor (or they may be great) don't let that discourage you if it does happen, come november with a proper tapper and more time to get used to the miles you should see large improvements.
Lastly, I doubt you are an 800m guy. It sounds like you are probably a 1500m/2mile/5k type guy who has good natural speed off low millage so you think you are an 800 guy, but if you develop that endurance to go with that natural speed I think you would make a decent miler/2 mile and probably a decent 5k guy in college. Who knows. (even if you are an 8 guy you need to be doing more miles anyway). Best of luck, enjoy high school summers and make them count, you don't get a second shot as you will find out one day.