Some legal databases offer alerting services. Alerting services allow you to set up a profile detailing the subjects that interest you. The database will then alert you by e-mail each time new material is added which matches your interests.
RSS stands for Really Simple Syndication. You can sign up to RSS feeds anywhere you see the RSS logo . These are updates that either 'feed' into your email inbox or into a 'feed' reader. These are usually free to set up and offer one place to collect all feeds as well as freeing up your inbox.