These PDF ebooks include a digital "pocket constitution" and annually updated editions of the Federal Rules of Civil Procedure and Federal Rules of Evidence.
The Federal Rules of Criminal Procedure govern criminal proceedings and prosecutions in the U.S. district courts, the courts of appeals, and the Supreme Court.
Affectionately known as Wright and Miller, this is one of the classic treatise for civil procedure and one of the classic treatises of law in general. This set covers all elements of federal practice, including civil, criminal and appellate procedure. The library currently subscribes to the print edition. The digital edition is available through the Westlaw link above.