There is a lot of discussion within the search engine marketing community surrounding the Google Penguin 2.0 updates and how they affect inbound links to your firm's website. In last month's issue of the Bigger Law Firm magazine, the author created a framework for how to think about search engine marketing moving forward. It's about connections, not just links to your website.
Connections involve social connections, citations, websites which mention your firm (even if not linking to it), inbound links, and outbound links. The outbound links are often overlooked, but are extremely important.
An outbound link is essentially an endorsement from your website -- an extension of your reputation. Imagine networking at a dinner party. You stand up and introduce your friend who has a Ph.D., is a professor at M.I.T. and currently works with NASA developing nuclear reactors to be used for galactic space travel. Your status at the dinner party is elevated by the fact that you are connected to your intelligent and interesting guest.
In a different scenario, you introduce your friend who was kicked out of high school after being arrested for a number of infractions, has never maintained any real employment, and now sits at a table at this party with wing sauce smeared across his face -- which he politely wipes off with the sleeve of his white button-down shirt. Your status at the dinner party is diminished by association with your friend.
Outbound links work the same way. Link to something of high quality and interest and it helps your website. Link to something of low quality, spam, or useless content and it could work against your site (or, at the very least, not help it).
When creating outbound links of interest, look to government websites, legal resources, law schools, and educations institutes. Making a connection with a high-value resource will help your visitors and help improve the reputation of your website.