Get a youtube channel:
https://www.youtube.com/watch?v=l0eM1_JVqHE
Personally:
I create a "video" using "Windows Movie Maker" because it's simple and quick (yet enough for my purposes).
For that program I link some fairly high resolution picture and have it run the duration of the audio recording.
Then I upload the resulting mp4 file to youtube (e.g.
https://www.youtube.com/watch?v=jbeMtu1dfkY