There are many prayers Catholics use to invoke the help of various Saints, Angels and of course, the Holy Trinity.
We have provided a web site that has a comprehensive list of prayers.
Spirit Daily.com - Spiritual News from Around the World
T H E C R O S S A N D T H E V E I L
Catholic Adult Faith Formation - Good News Ministries
Pennsylvania Pro-Life Federation
Homepage of Eternal Word Television Network, Global Catholic Network
Catholic Charismatic Center on the World Wide Web
Prayer to the Holy Spirit
Holy Spirit, You who make me see everything and showed me the way to reach my ideals, You who gave me the Divine gift to forgive and forget the wrong that is done to me, and You who are in all instances of my life with me, I want to thank you for everything and confirm once more that I never want to be separated from You no matter how great the material desire may be. I want to be with You and my loved ones in your perpetual glory. Amen. Mention your request. While making the request, promise to either publish this prayer or to circulate the favor. Say prayer for 3 days. After the 3rd day, the reuest will be granted.