You could also try to go with MPEG Streamclip at
www.squared5.com .
First you export the sequence as QT Reference, which will give you one .aiff and on .mov file, the .mov file links to the original footage in the MXF/Omfi Media folders.
Then in MPEG Streamclip you can choose from a variety of codecs and containers.
I would advise to export as .mov or .mp4 file using the H264 codec, and the bit rate as high as you want.
And select Multi-Pass if you have time for that (it takes two to five times longer in my experience, but the image quality is better, especially in fast moving takes).
I think YT now accepts videos up to 1GB though.
Give them the best quality you can offer and afford (bandwidth wise), as YT converts the video in the end to three/four different resolutions anyway.