Note:For those using a customized third-party template, you will have to add a snippet of code to make Jump Breaks work.
To do this, access your blog's Layout | Edit HTML tab, and first backup your template by clicking theDownload Full Template link at the top of the page. This will download an XML version of your template which you can upload later at any time if you need to.
After backing up your template, then click the Expand Widget Templates checkbox, and scan your HTML for the following snippet:
<data:post.body/>Once you've located that code, paste the following snippet directly below it:
<b:if cond='data:post.hasJumpLink'>
<div class='jump-link'>
<a expr:href='data:post.url + "#more"'><data:post.jumpText/></a>
</div>
</b:if >