Hi Chris,
If you don't have anyone HTML savvy, you can download some pretty great templates directly into your instance here:
templates.marketo.com. There's also a number of sites out there that sell customizable email templates.
For your own custom-built templates, you have to insert the finished HTML into the editor. Editable sections are marked by:
<div class="MktEditable" id="yourIDhere
"> CONTENT </div>You can name the ID whatever you'd like, typically section names like "main-banner" or "body-text" work well for teams.
What I think you're thinking of with drag & drop is when you're editing the actual new email itself. You can drag in images and tokens from the pane in the upper right corner and place those assets into the predesignated editable fields.
If it doesn't look cool, you're probably doing it wrong.