If you’re a lawyer, you’re locked into paying for either Westlaw or for Lexis-Nexis. Those are the dominant players in the electronic legal research market. But their services are awful. Very poorly constructed, very difficult to use, very slow, hard to learn a new search language.
Google is to the rescue, but expanding its search engine to include legal research. You can find state and federal court opinions, laws, etc. It’s fantastic, and will only get better with time!