Magento 1.7 - Creating Very Simple Extension

Magento 1.7 - Creating Very Simple Extension

I've been trying to create a very simple extension. Essentially I only
need to be able to store images / text with it, and then echo it on the
front-end. Now I've tried following different guides online and they seem
to be missing important elements because either the extensions don't show
in the admin area, or I get an error.
For example, I followed
http://inchoo.net/ecommerce/magento/create-configuration-for-your-magento-extension/
to the 'T', and I get the following error in the admin area when going to
Configuration:
Fatal error: Class 'Inchoo_Mymodule_Helper_Data' not found in
/home/apndev/public_html/app/Mage.php on line 546
Is there a better way of going about this or does a tutorial exist that is
current and works? Perhaps I'm missing a vital step somewhere?
Thanks!