for a list of the candidates running.

Many states have closed primaries, meaning that you have to be a registered Democrat or Republican in order to vote in their respective primaries. So you need to check to see whether you need to register as one of the party's members if you want to vote in the primaries.

To check politicians' positions a good website is http://www.votesmart.org
Other candidates that don't have a track record usually have their own websites.

As they always say,
Vote early and vote often.