How to contribute a Video?

I have created a video tutorial and want to contribute that video. Each time when I try to upload it causes an error after 10-15 mins.

The video size is 15mb and the format is mp4. I also tried to convert the video in flv format which is recommended but after converting to flv the video size becomes 84 mb. 

Can someone please guide me on how to upload video article. Also what is that video embed option?

 

Thanks,

Praneet