Top Ten Legal Research Things Law Students Should Know

Local law firm librarians are collaborating with the local law schools in an endeavor to better prepare law school students for their experiences as summer associates, from a legal research perspective. The end product will be a list of the Top Ten Legal Research Things every law school student should know before entering the law firm environment. I wonder what single legal research tool practicing attorneys would recommend that every law school student should know.  And to those who are a little closer to the law school experience, what single thing do you wish you had known going in?