Sorry, I'm a little annoying but I want to know how can I insert Statistics in my gallery. I have the plugin and I activate it but I don't know how to insert it. Can you explain to me all the phases I must do to make it work. Thanks.

No problem..:-) But first please try to get a little into it yourself. All info about the statistic functions is to be found here:
http://www.zenphoto.org/documentation/zenphoto/_plugins---image_album_statistics.php.html

If you have problems understanding the documentation please take a look here first:
http://www.zenphoto.org/2008/04/how-to-read-the-zenphoto-functions-guide/

And probably our theming tutorial, too: http://www.zenphoto.org/2008/05/theming-tutorial/

If that all does not help come back.