Getting the field of a user based on uid or name
I think if you need show more info of author of node, you can try this way.

STEP 1

in file template.php write hook_preprocess_node

function YOURTHEME_preprocess_node(&amp;$vars) {
  $node = $vars['node'];
  $user = user_load($node-&gt;uid);

  // if you want render field user
  $phone_render = field_view_field('user', $user, 'field_phone')
  $phone_html = drupal_render($phone_render);

  // if you want get value of filed
  $phone = field_get_items('user', $user, 'field_phone');
  $phone_value = $phone[0]['value']; 

  $vars['phone_value'] = $phone_value;
  $vars['phone_html'] = $phone_html;
}


use need change field_phone with your machine name of your field user.

STEP 2
In file node.tpl.php. You can use 

&lt;?php
  print $phone_value;
  print $phone_html;
?&gt;


print where you need.