We donate to all our daughter's schools, not inappropriate money, but plenty. Basically every fundraiser that comes up we donate to. They often accept donations of gifts to then raffle off as well.

If you want to directly donate, like say you want to donate new keyboards and peripherals to an under funded computer lab, or donate uniforms paid to the uniform shop so they can give them to families that can't afford them, that requires following a set of specific rules.

In that case (in my country) you have to go to the principal (just ask for a meeting) and ask what the process is. Pick a single thing you would like to fund per year, and go through the steps involved to fund it.

Ask to keep it anonymous if you prefer that, we never wanted anyone to know.