The Children's Literacy Initiative (CLI) provides professional development - through seminars, literature, etc. - for teachers of grades prekindergarten to third. There's a variety of evidence by external organizations that the CLI has a positive impact on communities in which it is active. (But do we really need someone to tell us more little kids being able to read is a good thing?) You can donate here.
The Children's Literacy Initiative has a four-star rating from Charity Navigator.