Creating a human head using the outline of a photograph

HI I am trying to create a human head using a photo of the front and side in a split pane view in blender. I have looked at loads of youtube tutorials and books which either miss out a crucial explanation of what they clicked on in the video or the books dont make sense. Does anyone have a link to a simple tutorial I can follow or can explain how after I have loaded the two images the process to follow? Much appreciated Gary

Moved from “Tutorials, Tips, and Tricks” to “Modeling”

Here is an older version tutorial but set up is the same in the current version.