How do I create a link to the author's profile on the node that user created? I want a create a link on each node page, which redirects to the profile page of the user who created that particular node.

How can I achieve this?
Create a custom block with this:

/**
 * Implements hook_block_info().
 */
function mymodule_block_info() {
  $blocks = array();
  $blocks['author'] = array(
    'info' =&gt; t('author'),
  );

  return $blocks;
}

/**
 * Implements hook_block_view().
 */
function mymodule_block_view($delta='') {
  $block = array();

  switch($delta) {
    case 'author' :
      $block['title'] = NULL;

      ////////////////////////////////////////////
      $link = NULL;    
      if (arg(0) == 'node' &amp;&amp; is_numeric(arg(1)) {
        $node = arg(1);
        if (!empty($node-&gt;uid)) {
          $link = l('view all work', 'user/' $node-&gt;uid);
        }    
      }
      //////////////////////////////////////////

      $block['content'] = $link;

      break;
  }

  return $block;
}


And set this block to nodes page with context, panels or native drupal blocks page.