Blender Help for Correct UV mapping

[Guipsou]

(Translated from french)
Hi all,
I'm a beginner in blender modeling and i need help to create correct UV maps for a project.

I know that meshes must have their own UV maps.
But should one UV map be linked to just one image / material, or multiple images / materials are allowed?

Here is an example of my mesh setup, i have several meshes like this, is this correct?

Screen link :
   
   
Thank you for answers and help.