Here is a list of websites that I have found useful for information and research for Catholic apologetics.
https://www.catholic.com/ (Known as the Catholic Answers organization, it has some great to-the-point articles on topics like the Sacraments, Intercessory Prayer, and Divine Revelation.)
http://newadvent.org/ (New Advent is a great site for reading when researching historical occurrences and biographies of famous people related to Church history.)
http://www.catholicbible101.com/ (Another great Catholic Apologetics site that deals with commonly cited anti-Catholic accusations.)
http://catholicapologetics.org/ (A Catholic Apologetics site dedicated to the biblical basis of the Church’s doctrines.)
http://www.scotthahn.com/ (The website of Dr. Scott Hahn, former Protestant minister, Catholic convert. There are some very informative articles on his website concerning Catholic doctrine.)
http://patrickmadrid.com/ (This is the website of one of my favorite apologists, Patrick Madrid. Patrick has great articles, especially concerning Mormons and Jehovah Witnesses.)