Layout for Magento module - magento

Question

I'm new in Magento and I'm trying to make a layout for a module I've build. I have a simple module and an IndexController which outputs 'Hello World.'(I've use this tutorial).
Now I want to make a layout for that module and I've used this tutorial but it doesn't work. Can someone point me to a tutorial or can explain me how layouts work in Magento?
Thx :)
Here's what I've done so far:
I have a package called 'Andrei' and a module 'Hello World'.
Here is the config.xml for my module:
<?xml version="1.0" encoding="UTF-8"?>
<config>
<modules>
<Andrei_Helloworld>
<version>0.1.0</version>
</Andrei_Helloworld>
</modules>
<frontend>
<routers>
<helloworld>
<use>standard</use>
<args>
<module>Andrei_Helloworld</module>
<frontName>helloworld</frontName>
</args>
</helloworld>
</routers>
</frontend>
</config>
Here is the Andrei_Helloworld module:
<?xml version="1.0" encoding="UTF-8"?>
<config>
<modules>
<Andrei_Helloworld>
<active>true</active>
<codePool>local</codePool>
</Andrei_Helloworld>
</modules>
</config>
And here is my controller:
class Andrei_Helloworld_IndexController extends Mage_Core_Controller_Front_Action
{
public function indexAction()
{
echo 'Hello world';
}
}
This is all I've done so far. The module works properly. And I want a layout for my IndexController. Thx :)

Answer 1

so, there is some stuff missing...
declare the layout update in the your config.xml:
<frontend>
...
<layout>
<updates>
<helloworld>
<file>helloworld.xml</file>
</helloworld>
</updates>
</layout>
...
</frontend>
create the layout xml file, in app/design/frontend/base/default/layout/helloworld.xml and in it you create a reference to your module/controller/action:
<?xml version="1.0"?>
<layout>
<helloworld_index_index>
<reference name="content">
<block type="core/template" name="helloworld" template="helloworld.phtml" />
</reference>
</helloworld_index_index>
</layout>
create the phtml file you've just set as template in your xml layout file, ie app/design/frontend/base/default/template/helloworld.phtml:
this is the content of helloworld.phtml
load and render all this stuff, in your controller's action, replace your echo statement with:
public function indexAction()
{
$this->loadLayout();
$this->renderLayout();
}
disable cache, refresh browser, sit back and enjoy