The teachings of the Catholic Church on the four last things might be summarized in the following points:

• Every person receives his eternal recompense in his immortal soul from the moment of his death in a particular judgment by Christ, the judge of the living and the dead (CCC 1051).
• Those who die in God's grace and friendship imperfectly purified, although they are assured of their eternal salvation, undergo a purification after death, so as to achieve the holiness necessary to enter the joy of God (1054).
• Following the example of Christ, the Church warns the faithful of the "sad and lamentable reality of eternal death", also called "hell" (1056).
• At the end of time, the Kingdom of God will come in its fullness. Then the just will reign with Christ for ever, glorified in body and soul, and the material universe itself will be transformed. God will then be "all in all" (1 Cor 15:28), in eternal life (1060).

Recommended Reading

• Read the Catechism of the Catholic Church, #988-1060 (Webpage)
• Dominican theologian Herbert McCabe's "The Four Last Things" is just about the most lucid account of this topic that you can find. (PDF)
• Philosopher Peter Kreeft offers his thoughts on eternity. Chatty read, but it goes deep quickly: "35 Frequently Asked Questions About Eternity (Webpage)."
• Popular theologian Frank Sheed has a readable but thought provoking treatment on the last things in Theology and Sanity. (PDF)
• For a slightly more dense take, see Monika Hellwig's  "The Kingdom of Heaven and the World to Come" in Understanding Catholicism (PDF)
• The Church tends to emphasize the four last things in at the end of the church year, especially with the celebration of the solemnity of All Saints and the memorial of All Souls. This website gives a nice overview of All Saints and All Souls, including many different Catholic traditions.