From YouTube’s website:

  1. Sign into your YouTube account.
  2. Click on Upload at the top of the page.
  3. Before you start uploading the video you can chose the video privacy settings.
  4. Select the video you’d like to upload from your computer. You can also create a video slideshow or import a video from Google Photos.
  5. As the video is uploading you can edit both the basic information and the advanced settings of the video, and decide if you want to notify subscribers (if you uncheck this option no communication will be shared with your subscribers). Partners will also be able to adjust their Monetization settings.
  6. Click Publish to finish uploading a public video to YouTube. If you set the video privacy setting to Private or Unlisted, just click Done to finish the upload or click Share to privately share your video.
  7. If you haven’t clicked Publish, your video won’t be viewable by other people. You can always publish your video at a later time in your Video Manager.