How do I do camera mapping of a person in a photo?

I want to take a photo of a character I like, and make a 3d model of her, using the photo as a reference. What process should I follow? Should I first learn how to model the basic human form? Perhaps I should start out from low poly person modeling?

if you have proper front and side views, you might wanna set them up as background images in blender.

i suggest you get into sculpting too, as its hard to polymodel all of it.

or

use " Shape from Motion "
there is a bundler add on for blender and other tools