I try to follow this tutorial: http://devdocs.magento.com/guides/m1x/magefordev/mage-for-dev-5.html
Problem is it doesn't work at all as Magento always tries to load the model from the wrong folder
Warning: include(Mage/My/Module/Model/Resource/Blogpost.php)
Here is my config.xml. The part with overwriting the success page works like a charm.
<?xml version="1.0"?>
<config>
<modules>
<my_module>
<version>1.0.0</version>
</my_module>
</modules>
<frontend>
<routers>
<my_module>
<use>standard</use>
<args>
<module>My_Module</module>
<frontName>my_module</frontName>
</args>
</my_module>
</routers>
<layout>
<updates>
<my_module>
<file>module.xml</file>
</my_module>
</updates>
</layout>
</frontend>
<global>
<blocks>
<my_module>
<class>My_Module_Block</class>
</my_module>
<checkout>
<rewrite>
<onepage_success>My_Module_Block_Onepage_Success</onepage_success>
</rewrite>
</checkout>
</blocks>
</global>
<models>
<my_module>
<class>My_Module_Model</class>
<resourceModel>my_module_resource</resourceModel>
</my_module>
</models>
</config>