I recently viewed a video of a talk entitled The Truth by Fr. Larry Richards, a Catholic priest from the Diocese of Erie, Pennsylvania. I had recently heard Fr. Richards speak at this summer's Steubenville St. Louis Mid-America, and was interested in seeing this video because of how well Fr. Richards seems to relate to his audience and get across a solid Catholic message. The video's a bit long, but it's worth every minute:
In a very short amount of time, Fr. Richards holds talks about many aspects of our faith, leading us to an understanding of 'the truth' about our faith—Jesus Christ. His 'truth talk,' some of his homilies, and a lot more information (including information on parish missions, teen retreats, etc.) can be found on the website for the Reason for Our Hope Foundation (Fr. Richards is the Foundation's president and founder).
This group's website is easy to navigate and contains a lot of good information; just make sure your computer speakers aren't turned way up! (There's a sound clip that plays on the home page).
In a similar vein, there are tons of great Catholic Apologetics articles on Catholic Answers Online that I go to quite often when I need to explain a part of our doctrine to non-Catholics.