Adding Custom Tabs in Product Detail Page

Just add this code after Description block in catalog.xml files

<block type="catalog/product_view_attributes" name="Your_attribute_name" as="additional" template="catalog/product/view/attributes.phtml">
    <action method="addToParentGroup"><group>detailed_info</group></action>
    <action method="setTitle" translate="value"><value>Your tab name</value></action>
 </block>

you can add in the above way for any number of tabs needed hope this helps.

Create the file app/frontend/design/{packageName}/{themeName}/layout/local.xml if it does not exist already.

Note: {packageName} is most likely "default" or "rwd", depending on your site setup. {themeName} should be a folder you created to use as the theme for your site, which extends the "default" theme.

In that local.xml file, include the following: (If this file already exists for you, just add the contents within the 'catalog_product_view' layout handle).

<?xml version="1.0"?>
<layout>
    <catalog_product_view>
        <reference name="product.info">
            <block type="catalog/product_view_attributes" name="product_details" template="catalog/product/view/attributes.phtml">
                <action method="addToParentGroup"><group>detailed_info</group></action>
                <action method="setTitle" translate="value"><value>Product Details</value></action>
            </block>
        </reference>
    </catalog_product_view>
</layout>