This entry in the FAQ covers most of it. However, YouTube changes the rules monthly. What works today, might not work in a week. Still, this should be you close. You may have to spend time on YouTube to see what their "instructions du jour" happen to be.
Did you get an error message with the failure? That might give people something to go on, to help you specifically. Also, a lot of folk at Muvipix upload a great deal of video to YouTube. You might want to post there too, as someone is likely to have this week's instructions.