Many law firms never update their legal web sites with new content or news about the firm. Its always a good idea to add new content to your site on a regular basis, because not only does this help the user experience and provide new information about your firm, but its also good for search engine ranking purposes.
Search engines like Google will favor sites that update content on a regular basis. So the more content and pages you can create of pertinent information related to your legal practice, the better your site should perform at the search engines.
Adding content is not the only thing you need to do in order to rank well at the search engines but it can make a difference if you have prepared and optimized your site for the search engines.