I have no practical experience with Squarespace. But, it's my understanding that you can create a fully functional podcast there, including the RSS feed that you can then use to syndicate to places like iTunes. Another option would be to let Squarespace handle your site and then sign up for Blubrry media hosting, and use a Blubrry Podcaster Homepage to create your podcast RSS feed. You can then link to the feed from your Squarespace site and use the Blubrry embeddable media player to display individual episodes. If you decide to do this, you can use promo code SHAWN to get your first month's service free.