What you will do is create one page that is a menu/list of all your users/customers.
for example:
<?php
// connect to db and ...
$query = "SELECT id,fname,lname FROM customers";
$result = mysql_query($query) or mysql_error();
while($row = mysql_fetch_array($result))
{
echo '<a href="edit.php?cid='.$row['id'].'">'.$row['fname'].' '.$row['lname'].'</a>';
}
?>
On that page you will link to a specific EDIT page, but you will pass an identifier through the query string to that page, so when the php script on that page is run, it will query the database for all the items you may wish to edit for that person and echo/print them into a form, by pre-populating the values for each textarea or input-text box.
That page could post to itself or to a third page. To process the changes you made using an UPDATE query.
Hope that helps........