http://www.nccbuscc.org/catechism/text/index.htm
The Catechism of the Catholic Church is a very lengthy document, so the NCCB/USCC online version is divided into chapter files to allow for faster download time on your computer.

http://www.liguori.org/cpr.htm
The Catechetical and Pastoral Resources Department (CPR) of Liguori Publications publishes books, booklets, nested programs, pamphlets, bulletins, bulletin inserts, prayer cards, and prayer services in both English and Spanish. In general, these works are pastoral, catechetical, biblical, spiritual, self-help, and educational materials.