directory usage

I can't see the footer status messages that tell me how much disk and database space my octopus instance is using. How do I activate it?

I'm at the beginning of a long learning curve on Drupal, with this question today.

My site will use a variety of photos and graphics. Is there any standard practice for where to locate these items? I'm assuming that creating a directory or two under /sites/all would be logical. That would give me

/sites/all

       /modules
       /themes
       /photos
       /graphics
       /videos         ....etc.