One go-to resource many of us use here at Pardot is Nvu. Prospect Insight has great built in tools for creating quick landing pages and emails from scratch, but in some cases you may have HTML provided by an agency or code pulled off your website that you want to tweak or update. This is where Nvu can be a lifesaver.
Nvu is similar to web authoring tools like Dreamweaver, but with one very important little difference – it is 100% free. It uses a WYSIWYG editor so you can just drop in your code, make your changes using the editor and copy the new code back in to your template. This can be great for updating your current emails or layout templates for future markeitng campaigns or for adapting the look and feel of your website in to new communcation tools.