The righteous, those who have received the ordinances of salvation and proven faithful to the attendant covenants, go into paradise at the time of their physical death. It would appear that all others, including the good and noble men and women of the earth who died without a knowledge of the gospel, enter into hell, outer darkness, or what is sometimes called (in a narrower sense than above- see Bruce R. McConkie, Mormon Doctrine, p. 755) spirit prison.
This second division is not simply a place of suffering, but also a place of preparation and learning. Joseph Smith taught concerning the necessity of ordinances for entrance into paradise:
“Every man that has been baptized and belongs to the, kingdom has a right to be baptized for those who have gone before; and as soon as the law of the Gospel is obeyed here [the gospel ordinance] by their friends who act as proxy for them, the Lord has administrators there to set them free” (Teachings, p. 367, italics added; see also D&C 138:58; Joseph Fielding Smith, Doctrines of Salvation 2:158, 230).