Permalink /author/steve-olaff uses the theme file author.php unless a more specific template is found.
Author.php includes a variable $author that holds the user ID of the author so the user data and meta data can be accessed using:
$curmem = get_user_meta(intval($author));
where $curmem is an array so data can be accessed using for instance:
This is because the array $curmem looks like:
[first_name] => Array (  => Peter )
or you can get a single piece of data using
$user_last = get_user_meta( $user_id, $key, $single );
where $user_id is an integer, $key is the array key and $single = true returns the value, false returns as array as above. eg
$user_last = get_user_meta( 9, 'last_name', true );
Would return ‘olaff’.
This coupled with custom user meta data can be used to generate a nice user profile page.