Ubuntu / Apache : how to check status mod_perl and settings

I have a Ubuntu Dapper Drake webserver.
I verified that perl is installed.
But I need to install some perl-scripts for a website.
When I put it in a cgi-bin directory the script wasn't executed but the
browser wanted to download the script. The directory and script have the
necessary permissions : 755. On a debian server I found several cg-bin
directories I tried to put the script everywhere but either the browser
wanted to downoad it or it wasn't found.

1. How do I check if mod_perl is installed ?
2. How do I install mod_perl ?
3. What about cgi-bin directory ? One per server or one per website ?
How to configure ?
4. Is there something else that I should do to use perl scripts ?

Thanx,

JM