The first isolated bead following the introduction is the beginning of the first decade. You may "go either way" around the loop of beads, and when beginning the first decade, ignore the medal.
A decade always begins with the "Our Father" recited on the isolated bead, then 10 "Hail Marys" recited on the following beads. On the last bead in each decade, also recite the "Glory Be..." and "O my Jesus, forgive us our sins, save us from the fires of hell, and lead all souls to Heaven, especially those most in need of your mercy. Amen" (from Fatima.)
Continue in this same manner through all five decades. After the fifth decade, say at least one concluding prayer on the medal; there is no set selection so you may use any prayer you feel is appropriate to the mystery upon which you have just meditated, or a prayer such as "Hail Holy Queen."