How should I go about doing meaningful academic outreach as a graduate student? I am a Hispanic student (senior undergraduate) from a socioeconomically disadvantaged background pursuing a graduate degree in Physics in US (I just finished submitting my applications). I do not know anyone from my neighborhood that attended college, much less pursued an advanced degree, and I find myself abhorred by the educational inequality in the US (and the world) on a daily basis. I've undertaken some personal outreach endeavors thus far, I act as a mentor via email for minority students in K-12 (for example, I send them updates about what projects I'm doing and links that I think are suitable for their age group) and I stay in contact with minority undergraduates in STEM whom find themselves faced with (socioeconomic) obstacles similar to those that I have faced.

My parents were hard workers, but they had little time (or money) to stimulate me intellectually as a child, and they also had no idea what it meant to pursue a PhD in anything besides a medical doctor. Thus, I really only became familiar with the notion of pursuing a career in scientific research when I arrived at college; prior to arriving at college, engineering was my idea of what it meant to be a "scientist", or, to "do science" as a career.

I would say that over the course of the past three years I have become a relatively successful researcher, and in some ways I have made up for lost time, but to this day I can only cringe thinking about where I (or someone in my same shoes) might be today if I had been exposed to science at a younger age. 

Does anyone have advice as to how I can begin making a significant impact in scientific outreach as a graduate student? I have a knack for programming, and the majority of my research is computational in nature, so I think I might be well suited for helping individuals learn programming remotely, or something of that effect.
Outreach comes in two flavours: creating interest (wow, this science thing is actually cool!), and educating (this is how you program). I think both are necessary, so take your pick (or both).

Also, don't even think of making it a one man effort. I don't advise to do it alone. There will be times where you will be swarmed in work, and then your outreach will just fall out of priority. Instead, team up with undergrads, schools, youth centres... whoever is willing to help you. If your university has something in place, you should probably go for it, as it will probably suit your primary needs the most. If you cannot find anyone, you can always start alone and get people on board along the way, but do make this a priority to ensure continuity.

Story time: when I was an undergrad, I joined the astronomy club at my university and we did a lot of outreach, mostly talks and workshops about different topics. It was a very good starting point, as I met people that have been in the business for some time, and could help me avoid some of the beginners mistakes. To give you an idea of our success, in some years, we (a dozen of undergrads), single handedly organised half of the events for the Science Week at the Physics Department, usually getting fully booked in less than a week since opening the registrations.

My experiences showed that:


Many teachers are overworked, underpaid, and frustrated; and they would take your activities as a way to relax for an hour. A few others are still passionate and will go out of their way to get you in the classroom and make the most of it.
Teenagers are difficult to begin with, but once you break the toughness layer, they have a bunch of interesting ideas. Also, beyond that point there are not many differences between posh and underprivileged schools.
Ideally, all fronts should be covered. This includes schools, family activities, talks for adults, elderly centres, giving teachers ideas... But of course, you don't have to do them all.
Be engaging. Get small groups, if you can. Prefer interaction in person. I wouldn't recommend teaching programming remotely, as it is too easy to ignore it. It would only work with kids that are really interested, but then, there are tons of online resources to learn.
Sometimes, kids behave like mushrooms, and there is nothing you can do about it. Don't let that frustrate you. Don't be impervious to (self) criticism, though.
Talk to professors active in outreach, even if they are out of your expertise. In my university there were a couple of them from the Optics department, that taught me a few nifty low budget experiments.