#7. Using the default permalink structure
A permalink is a permanent static hyperlink to a specific blog post in your WordPress blog. You would probably have noticed that WordPress default permalink structure is something like www.yoursite.com/?p=123. Not only does this look awkward, but also bad for SEO and users.
A user and search-engine friendly permalink structure doesn’t only help you get ranked higher in search engines, but also shows your professionalism to your readers. After you’ve installed WordPress, never forget to make changes to your permalinks structure, by going under Settings » Permalinks. To get the most out of your SEO efforts, use appropriate keywords in your permalink structure.
Read more at http://www.jeffbullas.com/2014/04/14/the-15-most-common-wordpress-mistakes-to-avoid/#0bwir6fhJUfddPBR.99