Magento – Helper Data not found – Can’t access admin panel

The module attributes on your xml elements should be Addschooltest, like the alias you gave your helpers in config.xml instead of Caitlinhavener_Addschooltest.
Off topic a bit: You might want to change this to a lowercase value. I mean:

<helpers>
    <addschooltest><!-- helper alias -->
        <class>Caitlinhavener_Addschool_Helper</class>
    </addschooltest>
</helpers> 

After that your adminhtml.xml file should look like this:

<?xml version="1.0"?>
<config>
    <menu>
        <SchoolMenu translate="title" module="addschooltest">
            <title>Schools</title>
            <sort_order>23</sort_order>
            <children>
                <myitem2 translate="title" module="addschooltest">
                        <title>Add Schools</title>
                        <action>adminhtml/addschool</action>
                        <sort_order>2</sort_order>                        
                </myitem2>
            </children>
        </SchoolMenu>
    </menu>
</config>    

You have to see what is the tag for the helper in app/code/community/Inic/Catalog/etc/config.xml. Search for <helpers>. Most probably it is:

    <helpers>
        <inic_catalog>
            <class>Inic_Catalog_Helper</class>
        </inic_catalog>
    </helpers>

then you have to use:

Mage::helper('inic_catalog/product_view')->gevalnow();

You have to replace inic_catalog with the string from the config.xml (below <helpers> tag).