The Chicago Manual of Style is often used as the citation style for history research.
Online Chicago Style Guide - from University of Arizona
APA Style Guides from Eckerd Library:
APA Style Guides Online:
Sample Papers in APA Format
MLA Style Guides:
Chicago Style Guides:
EndNote Web is a web-based citation management tool for organizing citations, which integrates with Web of Science.
Mendeley is another free citation management tool. It includes an online version, desktop version, and MS Word plugin for direct citations.
Zotero is a free, easy-to-use tool that helps you collect, organize, cite, and share citation sources for your research. It is a web browser add on and can be used with Firefox, Safari or Chrome.