Anything like khanacademy.com?

[Blanquist]

That site has a very small history section, is there anything else like it that explains Das Kapital, socialist history, etc?

[BE_]

No, Not to my knowledge. That would really be a good idea though. There might be videos on youtube explaining things like that.

[Ethics Gradient, Traitor For All Ages]

http://kapitalism101.wordpress.com/
And http://davidharvey.org/ are both very helpful if you are reading capital for the first time