Below are various websites to help you with your research.

MCHS Destiny 
GALILEO - 
ERIC
100 Search Engines for Academic Research

National History Program
National History Education Clearinghouse

NHD Teacher Resources
NHD Noodle Tools  
National Archives
Georgia Encyclopedia
Library of Congress
Chronicling America - LOC

References and Citations
Citation Machine
Easy Bib

Primary and Secondary Sources Help
Compare and Contrast Sources
Distinguishing between sources
Sources in History

Historical Photos
LOC Historical Photos Project
NYPL Historical Gallery
National Museum of American History

Metasearch Engines
Ixquick MetaSearch
Dogpile

Academic Research Websites
Base Academic Search Engine
RefSeek Academic Search Engine
Google Scholar
Virtual Learning Resource Center
American Memory - Library of Congress
Worldcat
Librarian's Internet Index
NASA Research
National Agricultural Research 
Smithsonian Institute Research Info System
The British Library
State Legislative Websites Directory
Directory of Open Access Repositories
U.S. Government Publications
Online Journals Search Engine