How do i upload to youtube?

I have converted vinyl on a usb turntable which goes directly to itunes so I have to convert it from Itunes and it converts to an m4a file, then i have to convert that to a wma file in order to be able to add it to windows movie maker so i do all the conversions add a nice picture to movie maker with the track playing and it plays perfect but when i try to upload to youtube there is a message saying 'the upload failed due to an unknown error' what am i doing wrong and is there an easier way of doing all this?