You'll probably find diagnostics useful while you're getting used to strict and warnings. It causes perl to spit out more verbose errors and warnings.

For example:

use strict;
use warnings;
use diagnostics;

$x = 4;

__END__
    (F) You've said "use strict vars", which indicates that all variab
+les
    must either be lexically scoped (using "my"), declared beforehand 
+using
    "our", or explicitly qualified to say which package the global var
+iable
    is in (using "::").
[download]