The Catholic Diocese of Arlington, Virginia, offered a list of thoughtful Earth Day resources, but opted for print-based PDF files. Yet at best, PDFs are okay for providing forms and such that are designed exclusively for printing. Other than for that purpose, “PDFs are evil” and “unfit for human consumption” say the usability experts.

Now I understand that the diocese was repurposing material a local parish developed the year before and was looking for an easy way (for the developers, that is) to quickly post the information. But when promoting conservation, why choose a document format that encourages unnecessary printing to read instead of regular HTML and embedded links?

Do we really need another roundup post of best practices for blogs? Not anymore because Tom Johnson of I’d Rather Be Writing has put together the definitive list of 20 principles for usable and readable blogs. The post offers good advice you may have seen before, but it’s carefully edited, includes solid examples and contains links to helpful plug-ins. What’s more, you’ll find about 30 links to the original posts that inspired the column — a step that less conscientious bloggers skip. Nice flagship content, Tom.

The only blogging point not covered that often comes up is whether or not to display social media bookmarking options, such as Digg and del.icio.us buttons, and Technorati tags. Here’s a summary of the list.

1. Pick a topic for your blog
2. Encourage comments
3. Make it easy to subscribe
4. Include an About page
5. Present your ideas visually
6. Keep posts short and to the point
7. Use subheadings for long posts
8. Link abundantly
9. Make headlines descriptive
10. Archive by topic
11. Include a list of related posts beneath each post
12. Allow users to contact you offline
13. Present your real viewpoint
14. Write for your future employer
15. Include a Top Posts section
16. Provide an index
17. Get your own URL and match it to your blog’s title
18. Include a Recent Posts section in your sidebar
19. Reward commenters for commenting
20. Post often

If you like Tom’s post, Daily Blog Tips, is another site that will give you a regular fix of similar advice.

What would you add to the list?

Think you can’t measure ROI for your non profit or church site? Here are seven measurements from usability guru Jakob Nielsen’s discussion of the ROI for non profit and government sites.

1. Double your conversion rate for subscribing to your email newsletters
2. Decrease phone calls for routine information, freeing up staff or volunteers for more meaningful tasks
3. Recruit volunteers more effectively and in less time
4. Help the environment by moving registration activiites online rather than through the mail or via paper forms
5. Retain more volunteers longerer by removing processes that sap their patience
6. Decrease abandonment rate for donor/volunteers who don’t feel your charity is trustworthy
7. Improve your success rate for the registration and checkout process for online donations

Even if your information is “just” informational, Nielsen argues it’s there for a reason so it’s worth designing your site right. So, which of these would sway your boss, board or council to give you a few bucks for usability testing?