Use the SimpleScreenRecorder to capture the screen while presenting.
Select the window area to capture (including a possible embbeded video of the speaker).
Embedded video of the speaker
Embedded video can be obtained by starting VLC and configure it to use a minimal interface in the View menu.
Change the window properties to be above others in the left and top most corner of the window.
Place the window in a convenient place of the recording area and resize to a convenient size. See figure below.
Editing the video
Using OpenShot to edit the video(s).
Drag in the appropriate clips and stills to the timeline.
See a short video of the setup here edited in OpenShot.
Export the final result to HD 1080p ogg format, which Youtube happily eats.