There are two methods for linking to your podcast in iTunes:
Music Store Link: The following link goes directly to your podcast page in iTunes, where users will have the opportunity to subscribe to the podcast. This link can be found for any podcast by holding down the control button on your keyboard and clicking on the podcast artwork or symbol on the feeds main page within the store (or right click in Windows on the artwork).
Direct Subscribe Link: The following link automatically subscribes the user to the podcast in iTunes. Note - this method doesn't work for Windows users who do not have iTunes installed, so it should be clear that the link is intended for subscribing with iTunes only.