Just a little info that should answer alot of PayPal questions! A complete manual all about PayPal Payment Integration into your website; written by PayPAl.

1. Login to your PayPal account.
2. Click on "Merchants Services" tab.
3. Click on "Website Payments Standard". (Left side)
4. Click "Website Payments Standard Integration Guide". (left side, in the box titled "Inside Website Payment Standard").
5. If you have Adobe Reader; the manual will open in the reader and then you can "save" it where ever you choose.

It has answers and many step by step instructions to do the things we want to do with the PayPal buttons!