[rake]

start with a blank page,
require("./global.php");
to get the vb back-end, so you can access vb resources..

Get your database structure straight. One table should be enough to start with. Something like id ; title ; definition will work.

if($_REQUEST['do'] == showletter)
{
globalize($_REQUEST, array ('l' => STR));

$l = $DB_site->query("SELECT * FROM table WHERE title LIKE '$letter%' ORDER BY title ASC");
while($def = $DB_site->fetch_array("$l"))
{
.....
}
}

This should be enough to get you started. You can work your way up from there. If you don't know what something is, just search here, or through the vb files, and you'll find it.