Paypal: Trial period subscription

I have only found limited documentation on how to add a free trail to a subscription.  I know there is a free trial option which can be set in the PayPal subscription settings. But how does this work exactly.  I set it to 3 days for example.  I am assuming that after those 3 days the customer will be charged automatically correct?  Will I receive their form information immediately, or only after the trail period is over and they have been charged?

Also, in the event a customer wants to cancel the subscription before the trial period is over, what is the process for that?  Is it something the customer can do on their own via some type of automated link? Or, will the customer have to contact us and then we go in and cancel.  

Really I just want to know exactly how this will work for the customer and for us.

When setting up a recurring subscription, if you enable a trial period you will be notified on submission. But the customer wont be billed until after the trial period.

Here's a guide: How-to-Setup-a-Recurring-Payment-Option

If your customer doesn't want to continue they can cancel their subscription on the Paypal site.

Ok, thank you for the link and answering my questions.  It seems that canceling a subscription is handled by the payment processor so I will contact PayPal to figure out how to make that process as smooth as possible.