What you are looking for is the sort function.

However, I think you are over complicating things somewhat.
Consider the following:

#!/usr/bin/perl
use strict;
use warnings;

my %people;

while (my $line = <DATA>) {
    chomp($line);
    my ($person, $occupation, $hours) = split /\s+/, $line;
    $people{$person}{occupation} = $occupation;
    $people{$person}{hours} = $hours;
}

for my $person (sort keys %people) {
    print "Name: $person\n";
    print "Job: $people{$person}{occupation}\n";
    print "Hours: $people{$person}{hours}\n";
    print "------------------\n";
}

__DATA__
Mike Plumber 80
Laura Programmer 60
Mark Sales 70
Jeremy Cook 65
[download]

Does this do what you want?

Cheers,
Darren :)