EZ Paypal allows you to add a custom PayPal button to your site. It's as easy as selecting some options and entering your Paypal email address!
There are several forms of payments that you can accept:
Buy Now buttons allow for one-time payment. You can also optionally specify discounts, taxes, and shipping.
Subscriptions allow you to setup automatic, recurring payments based on days, weeks, months, or years. Subscriptions do NOT apply to group permissions; they only apply to recurring payments.
Also, keep in mind that if you use the Subscription payment method, you will need to deal with cancellations manually.
Donations are rather simple. Just enter a value for the base price, and that's really all you need. Donations are one-time payments.
Due to the nature of this addon, the Paypal buttons are NOT necessarily secure! However, the Paypal checkout page itself is secure.