Magento: How to add a new block?

If you want to reference a static block from inside of a CMS page or another static block use this syntax:

{{block  type="cms/block" block_id="my-new-block"}}

If you want to reference a static block from Layout Update XML use this syntax:

<block type="cms/block" name="position-9">
<action method="setBlockId"><block_id>position-9</block_id></action>
</block>

If you want to reference a static block from a PHTML file use this syntax:

<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('my-new-block')->toHtml() ?>