After you installed PHP-PDB somewhere, just use your web browser and view pdb-test.php. It will perform a few tests and tell you the results of the tests. They should all say pass. If they don't, contact me for help. You can see how the test looks for this installation, but you will want to also test it on your machine.
There are mailing lists set up so that you can get announcements of new versions and participate in a general discussion about PHP-PDB. If you are asking for help, please subscribe to the general mailing list and ask your question. Your answer should come to you pretty fast. If you abhore mailing lists and would greatly prefer to not subscribe to one, just email me directly. I'll simply forward your request to the mailing list and then ask that the list members reply to you and to the list. My email address is at the bottom of the page.
PHP-PDB is released under the GNU LGPL and is basically free to use for everyone. Please see the LGPL for specific details.