In addition to David Harvey's lecture series - http://davidharvey.org/reading-capital/ - the following links may be useful:
http://vol1.polyluxmarx.de/en/home.html (a slideshow series produced by the Rosa Luxemburg Foundation, quite user-friendly)
http://content.csbs.utah.edu/~ehrbar/akmc.htm (a set of annotations to Capital and other works by Hans Ehrbar, an economics professor fluent in English as well as German)