If you plan to have your own layout for form, you may do so by adding a template file based on your module name.
Example:
<?php
[modulename]_theme(...) {
return array(... ,
"[modulename]_node_form" => array(
"template" => "[modulename]-myform",
"arguments" => array("node" => NULL)
);
?>Your file name will be [template] + ".tpl.php".
Example: [modulename]-myform.tpl.php
If no theme is declared by that name, "node_form" theme will be used instead.