I'm not asked about this topic very much, but I figured since it's become a bit of a speed bump in working through the Google+ authorship verification process, it would be good to address it. The "speed bump" is essentially that when using the rich snippet tool or looking for the thumbnail by your search engine results, it will only show up if the version of the site your testing is the same version of the site that you entered into the "contributor to" section on your Google+ profile.
Every website basically has two addresses. For instance, this website is accessible by going to http://www.swell-sites.com or going to http://swell-sites.com. Grant it, if you access the non-www version, it will re-direct you to the www version. We do this through a simple line of code provided through an htaccess file.
If you're just getting started with your web presence, it really doesn't matter. People who type your website address directly into their browser will be able to access your website regardless of whether they enter the www or the non-www version. The reason that this matters is because if you don't designate which version you'd like to use, then you can effectively split your SEO and linking efforts by using both. When you link external properties to your website, you want to make sure that you are pointing that link to the same version that Google is recognizing.
If you did not address this issue when you first published your website, you're going to want to use the version that is already recognized through Google. The best way to do this is to simply run a search, either that you know you already show up for, or for your business name, or domain name.
Here is an example of a site where you would want to use the "www" version.
Here is an example of a site where you would want to use the "non-www" version.
Once you have figured out which version to use, you're going to want to enter code into your htaccess file to either redirect the www version to the non-www version, or vice versa. Simply ask your web developer to take care of this for you. If you manage your own website, running a few simple searches about how to create an htaccess file and redirect one version to the other will give you a plethora of resources.
If you have questions about your current website, or how to increase your position on the search engines for your law firm, I'd love to talk to you about it. Feel free to call me or contact me via email through this website.