Ask HN: Experience managing volunteer software developers?

I've gotten myself into a leadership position at a non-profit helping to build out their tech (simple web app frontend+backend). Since the organization has only a small amount of funding, they cannot yet afford to hire a full time developer. Therefore I am hoping to move forward with the help of volunteers. I'm wondering if anyone here has ever managed volunteers, and if so do you have any tips? In particular:

1. How did you find volunteers?

2. Did you do anything special to make it a more valuable experience for them?

3. Did you do anything to make do with the smaller amount of hours they could give?

4. What management software/system did you use?

Any other insights or stories are much appreciated!