Erowid is pretty much the best site out there when it comes to spreading the word of drugs and harm reduction.
You can donate here!
When shopping via amazon, you can use this link to donate 0.5% of the price of your eligible AmazonSmile purchases to the charitable organization of your choice, such as Erowid or MAPS.
If you're interested in helping out Erowid directly, check out their volunteer form :)
Done. Upvote. I donate my change after every order.