The Chicago Manual of Style Online - Quick Guide
Purdue OWL Chicago Guide
These citation management systems make it easy to save citation information as you're researching. They even generate bibliographies for you in the style of your choice. Take a look at their sites to see which one will best meet your research needs.
A free browser add-on that imports and formats citations from databases and the internet. Also serves as a versatile notetaking platform.
Free to everyone, this tool is oriented towards saving and annotating research.