Prior to the year 1234, the Church did not have a formal process of beatification. Usually martyrs and those recognized as holy were declared saints by the Church at the time of their deaths. Beginning with Pope Urban VIII in 1634, various Popes have revised and improved the norms and procedures for canonization.
Today the process proceeds as follows: When a person dies who has "fame of sanctity" or "fame of martyrdom," the Bishop of the Diocese usually initiates the investigation. One element is whether any special favor or miracle has been granted through this candidate saint's intercession.
At one time, saints were popularly proclaimed. As you may recall, the same thing happened upon the death of JPII. In April of 2009, Pope Benedict XVI, told Pilgrims gathered in Rome "With you, I pray for the gift of beatification". Friday, January 14, 2011 the Holy See released the "Decree for the Beatification of the Servant of God John Paul II." The full decree is found here.
Deacon Keith Fournier wrote a beautiful and detailed argument for the beatification of JPII which you can read here.
Already several miracles have been attributed to his intercession. It only took one to begin the beatification process that will culminate on the Feast of the Divine Mercy, May 1. Hope you can tune in and watch. Millions are expected to pack Rome to join in the celebration of our beloved Pope John Paull II's beatification.