See below for a voting guide prepared by the United States Conference of Catholic Bishops (USCCB). It is a “guide” – it does not attempt to tell Catholics exactly how to vote. And it is not a partisan document (one will find that Catholics do not fit neatly on one side of the conservative/liberal divide). Political decisions are prudential judgments, and each person must make prudential judgments for themselves. A prudential judgment is a judgment where a general principle is applied to a particular situation.
The purpose of the document is to clearly articulate the moral principles that Catholics find binding (these moral principles are taught by the authority of the Church but are also discoverable by natural reason and should be recognizable to a person with a well-developed conscience).
It is a nice outline of Catholic moral principles as they relate to various political and social issues.
Click here for a link to the USCCB document.
Click here for a summary, it is more manageable though it sacrifices some nuance.