How do I set up a recurring payment in the Sandbox and how similar is it to live PayPal?
The Sandbox is theoretically identical to the Live environment. In practice, there are some differences — mostly in the Sandbox being broken in one way or another quite often. You will want to use it to test your recurring payments, though. Any code you create for the Sandbox will work with very minimal modification in the Live environment. You only need to change usernames, passwords, URLs, etc. In order to set up recurring payments, you first need to decide whether you want to use Website Payments Standard or Website Payments Pro. The best place to start researching that is the Integration center here: https://www.paypal.com/IntegrationCenter/ic_home.
