I'm not sure if this is actually a Perl/CGI question - it's more HTTP and HTML - if you want to pass arguments to another page use:

<a href="random_page.cgi?arg1=foo&arg2=bar&arg3=baz">Random Page</a>
[download]

or

<img src="random_page2.cgi?arg1=foo&arg2=bar&arg3=baz">
[download]

You get the idea.

It's the same idea whether it's a perl script, php page, ASP *Gaaak* page, or whatever.
For an example of this, look at almost any page in the Monastery...

Pulling out the arguments you pass to your script in this fashion (or via the POST method) will require the modules belg4mit mentioned.

Update: wog++. Taking wog's post a bit further, it's probably a good idea to do URL Escaping - pass all strings like the URLs I've written above through URI::Escape or CGI's escape() in order to correctly handle difficult arguments.
It's something I've got into the habit of - IMHO it's worth having a sub urlEncode in bigger systems.