Within 10 days of the initial appearance for in-custody defendants, and within 20 days of initial appearance for out-of-custody defendants, a defendant is entitled to a preliminary hearing or arraignment. See Fed. R. Crim. Pro. 5.1. There are federal grand juries sitting at all times in the Northern District of West Virginia, so a defendant may be arraigned on an indictment at the arraignment hearing, instead of having a preliminary hearing.
An indictment is a formal charging document that contains the federal charges faced by the defendant. It is reviewed by a grand jury, and if there is sufficient evidence to force the defendant to face the charges the grand jury "signs off on the indictment (or returns the indictment.") There can be additional indictments brought in one criminal case - later indictments are called "superceding indictments."
At the arraignment, the magistrate will issue a scheduling order and note which district court judge will preside over the case. A district court judge, or "Article III" judge, is appointed by the President, confirmed by the Senate, and serves for life. With the exception of pre-trial motions hearings which are heard by the magistrate, the district court judge will preside over the rest of the case, for the later trial or plea hearing, and for sentencing if necessary.