Complete newbie here, but I just did much of this yesterday, so here's what I did...
Test each individually first if you haven't already. :
Point a browser to http://localhost
and see if the Apache page comes up.
Next try running mysql from a console. If you haven't configured it yet, mysql -u root should let you in. If that works mysql is up and running.
Finally, build a quick PHP page and place it in the html directory (on my mandrake build I think it's /var/www/html) and call it. If that works, you have Apache and PHP happy. Then just modify the PHP to query the MySQL db and put it to page.
Much of that assumes you're familiar with PHP and MySQL. If not, you can get some help on how to build a quick PHP script and a database to query with it.