I can not fine a simple turtoails about chang my skin (template) for my store.

I use (Template Packages) download Apple Zen Template.
then copy it near classic and default in this addres in my host:
/includes/templates/...


But in admin in change template there is not my new template (Apple Zen Template). how can I configure and install (Apple Zen Template)

is Apple Zen Template a skin for my store?

How can I get a preview before install a skin.

Thanks