4. The Resume
I think that not many high school students know how to write good resumes, being that they there really isn't a need for one during most of high school. My friend a couple of years back gave me a good template to use, and I'll give it to you.
There are two options: the "profesional" 1 page version (that everyone in college and the real world uses) and the format that my friend gave me
Type 1
Type 2
The word doc is the professional kind and the pdf is the one I used when applying to colleges (though I didn't send it to MIT because I made it too late).
You can use whichever one you want, but I'd recommend the pdf type for now.
Remember that formatting and presentation matters a lot. If you just list everything you've done on a sheet of paper with size 12 Times New Roman font, that probably won't be too impressive.
If you want, you can search online for resume formats, but I'd avoid the 1 pager for now because it doesn't provide much information about you (its real purpose is to get you a job interview, so you don't want to give away all that's hidden up your sleeve before the interview, but since you're not going to have another chance to explain the things on your resume it's better to give the full monty).
Mail this resume to MIT in a large manila envelope with cover sheet that has your name, home address, and MIT ID on it (if you're applying online, as I did last year, send it in like this anyway).