[development] modify the output of nodes (hooks??)

[Alex Moreno]

Good afternoon,

im working on a custom module (my first one) and i have a question.
I´d like to modify the output of the nodes, such as modules like print
does. I´ve been reading about the hook funcions but i´m not sure about
the better or most advisable way.

For example:

function monedas_block($op='list', $delta=0) {

  // listing of blocks, such as on the admin/block page
  if ($op == "list") {
     $block[0]["info"] = t('Monedas');
     return $block;
  }

  else if ($op == 'view') {
     	$block['content'] = "contenido del bloque";
     	return $block;
     }

} // end monedas_block


¿is this method correct? Is there any good lecture about it?

Thanks a lot.