Build a Little Free Library. As a book lover and a community builder, I’ve always loved the idea of the Little Free Library. And, we’re lucky to have two within a couple of blocks of our house (one a residence, one a business). Each Little Free Library is registered online, so you can even see if there already is one near you.
To this I will add that there are multiple variations on this theme, including but not limited to Little Free Seed Libraries, Little Free Pantries, Giveboxes, and Official BookCrossing Zones. You get the idea. Just make some kind of space for folks to help each other out and replace the economy of greed with a gift economy. Note that these tend to heterodyne: if you have a whole network of LFLs or one of each type of freebox, your community will seem like a welcoming and generous place.
What if they get banned? What if they get trashed? Then you know something in your neighborhood is fucked up. Go fix it. Then try again. These things make fantastic canaries.
EDIT 2/9/19: If your neighborhood already has such facilities, then you can help by making a habit of loading them. Buy used books, or new ones on topics or authors you wish to promote, and release them into the wild. For LFPs, staples such as beans-and-rice with a spice kit work very well. Giveboxes are well suited to outgrown clothes and the like, but don't overlook the option of buying stacks of cheap coloring books and crayons at a dollar store when school lets out.