I also quoted from the message which Pope Benedict wrote for Vocations Sunday before he retired. You can read the whole of his message here.
Above all, pray for vocations. You might like to use this prayer which was very important to me as I discerned a way forward at a significant time of my life.
Lord,
Make me a better person,
more considerate towards others, more honest with myself, more faithful to You.
Make me generous enough to want sincerely to do your will whatever it may be.Help me to find my true vocation in life and grant that through it I may find happiness myself and bring happiness to others.Grant, Lord, that those whom You call to enter the Priesthood or Consecrated Life may have the generosity to answer Your call, so that those who need Your help may always find it.
I ask this through Christ Our Lord, Amen.