[Lynne]

Go to the template blog_list_entries and find this line and just add your div/block above it:

    <div class="block" id="whatsnewsidebar">

If you look at the others, you should make it something like this:

<div class="block">
<h5 class="blocksubhead smaller">title</h5>
<div class="blockbody">stuff</div>
</div>

It may not be totally accurate - take a look at the other blocks to verify the format.