History.com has a terrific interactive site featuring Black History Milestones (this link takes you to the page on Jackie Robinson breaking baseball's color barrier). Perfect if you're looking for a reliable yet accessible starting point for Black History Month!
You'll especially appreciate the slider which allows you to move from early events such as the introduction of slavery in the Americas to more recent events including the election of President Obama. The site includes archival images and video to supplement the article accompanying each milestone. Additional resources including maps and biographical profiles can be found on the site's Black History homepage.