In the blogs

From Nongeek Perspective: 5 Ways to Contribute to Open Source Projects Without Coding. Here he (or she? not clear) condenses advice in two other pieces (below) to six categories of non-code contribution:

1. Quality
2. Documentation
3. Support
4. Money
5. Publicity
6. Appreciation

http://nongeeksight.blogspot.com/2006/09/5-ways-to-contribute-to-open-source.html