Magento helper methods do not work - magento

Question

So this one is a bit odd. I'm sure it's old hat to some now, and I've just done a bad job searching it out. If that's the case I certainly apologize and ask for your indulgence and a link to the already provided answer.
So I have followed the core guides for creating a magento module, but for some reason it does work right. When I var_dump the helper class it has the correct name, but when I try to use one of the methods I've put in the class definition it throws an exception.
Furthermore, when I run get_class_methods() on the class given to me by Mage::helper('mymodule/myhelper') none of my methods are there.
So in summary:
The class is in the right place, app/code/local/MyModule/Helper/Myhelper.php
The class shows as initialized after I call Mage::helper('mymodule/myhelper')
The class methods are not listed, and as a result, break things when called.
Here's my config for reference. The rest of the module seems to be fine.
<?xml version="1.0"?>
<config>
<modules>
<APCShared_Shipping>
<version>0.1.0</version>
</APCShared_Shipping>
</modules>
<frontend>
<routers>
<apcshipping>
<use>standard</use>
<args>
<module>APCShared_Shipping</module>
<frontName>apcshipping</frontName>
</args>
</apcshipping>
</routers>
</frontend>
<global>
<blocks>
<apcshipping>
<class>APCShared_Shipping_Block</class>
</apcshipping>
</blocks>
<helpers>
<apcshipping>
<class>APCShared_Shipping_Helper</class>
</apcshipping>
</helpers>
<models>
<apcshipping>
<class>APCShared_Shipping_Model</class>
<resourceModel>shipping_resource</resourceModel>
</apcshipping>
<apcshipping_resource>
<class>APCShared_Shipping_Model_Resource</class>
<entities>
<zipcode>
<table>apc_shipping_zipcode</table>
</zipcode>
</entities>
</apcshipping_resource>
</models>
</global>
</config>

Answer 1

In the admin somewhere under System > Configuration > Advanced ensure your module has been registered.``
Make sure you have the class APCShared_Shipping_Helper_Data in the Helpers folder in a file called Data.php. Your class should extend Mage_Core_Helper_Abstract
Access your helper with Mage::helper('apcshipping')
Your directory structure should be something like:
- Module Folder
- etc
- config.xml
- Helper
- Data.php

Answer 2

In your file structure, point 1 of your summary, you are only using a modulename, not a packagename.
So it should be: app/code/local/MyCompany/MyModule/Helper/Myhelper.php instead of app/code/local/MyModule/Helper/Myhelper.php.
I'm not sure if this will make a difference, but it's always good to follow the coding convention.