Source: http://moz.com/blog/15-seo-best-practices-for-structuring-urls
Site URLs and domain names are one of the few basic principles of Search Engine Optimization. This serves as a guide in optimizing your permalinks to increase effectiveness of how Google crawls your pages.
15 ways to structure your URL
- Use a single domain & sub domain – your blog and your site can perform better everything is part of the root domain.
- Make URLs readable – increase click through rate for optimized URLs
- Place keywords in URLs – URL is also considered by searchers when clicking a site
- Avoid multiple URLs with the similar content – user 301 redirect or rel=canonical to avoid split ranking signals
- Exclude dynamic parameters when possible – avoid URL parameters to increase click volume
- Shorter URLs are better – increase user experience by limiting the amount of characters on URLs (less than 100)
- Make sure that your titles and URLs match – aim for similarities between URLs and your page titles
- Including stop words isn’t necessary
- Remove/control for unwieldy punctuation characters – avoid hard to read characters on URLs
- Limit redirection hops to two or fewer – browsers are slowed down due to long redirect strings
- Fewer folders is generally better
- Avoid hashes in URLs unless absolutely essential
- Be wary of case sensitivity – you’d want URLs automatically redirect to the correct URLs when the wrong case is used (ex. /example.htm and /ExaMplE.htm)
- Use Hyphens and underscores for word separators
- Avoid keyword stuffing on URLs