SEOmoz blog has a helpful post with 11 Best Practices for URLs. They’re mainly written from an SEO perspective although make sense on other levels also.
- Describe Your Content
- Keep it Short
- Static is the Way & the Light
- Descriptives are Better than Numbers
- Keywords Never Hurt
- Subdomains Aren’t the Answer
- Fewer Folders
- Hyphens Separate Best
- Stick with Conventions
- Don’t be Case Sensitive
- Don’t Append Extraneous Data
I’d add one more.
12. Breaking the above practices doesn’t guarantee poor SEO results. While they will help there is hope if you break one or more of them. For example here at ProBlogger I use ‘archives’ (a non descriptive) and the date (numbers) in the URLs of my individual pages (both making the URL longer and breaking a couple of the other practices). While this is definitely not ideal I still do pretty well with SEO.
Most of the above practices are the type of things you need to think about when you’re setting up your blog. Changing your URL structure midstream can be a little tricky so unless it’s terribly bad and you’ve got other SEO factors working for you it might actually be best to keep the structure you’ve got.