I need help using PayPal IPN with PHP. Does anybody know where I can find some good tutorials? Thanks, Ryan
Check the paypal developers area: https://developer.paypal.com/. They have full scripts for IPN and every other integration method. Personally, I recommend using Express Checkout if it makes sense to your checkout process. It is a much more robust system, and integrates better with the back-end of websites.
PayPal has some great resources on the site jestep linked to. They also have a community as well with some very useful information. Some people like this class for use of IPN. But be sure to check out jestep's link as well, as there are a lot of good, documentated examples that you can utilize.