Integrating Paypal Into HTML Page

Answer 1

For a basic HTML page, use PayPal's own button wizard. Just go to Merchant Services -> Add to Cart button. It will allow you to customize the button to specify different sizes via a drop down and even select a quantity when the item is added to the cart. You can also add a "view cart" button as well and everything is taken care of for you. I used this on a recent site.

Granted adding items and viewing the cart takes the user to a PayPal page, but unless they're looking for a fully integrated site, this option is fast, easy, and robust. Plus PayPal does a good job at tracking where the order page is coming from so the user can easily navigate back.

Answer 2

I used the paypal developers website at http://www.paypaldeveloper.com/pdn/.

There are a lot of very helpful programmers there.