Best place would be to look at:
http://www.php.net/manual/ref.session.php
But to put all that in brief:
$moo = "cow";
// to register the variable to be used across the session
session_register("moo"); // notice no $ on the var name
// to display the session variable on another page
session_start(); // this needs to be at the top of your page, before the tag
echo $moo; // same as using a local var
hope that helps,
-Sean
