Problem :(

[Dinocanid]

I remember installing that theme once, so it should work. In your files, they should be set up like this:

Public_html --> templates --> bookstore (including all of the contents in it's folder)

Then did you go to the adminCP, click on add/install new theme, then add the theme name and folder? (It's case-sensitive, so don't use capital letters if there aren't any). Afterwards, you would go to the general site settings and change the default theme to bookstore.