Integrating PayPal links to a php website

I'd like to integrate PayPal links seen on this webpage:

http://img804.imageshack.us/img804/1340/paypale.jpg

The two links lead to this "checkout" page:

http://img705.imageshack.us/img705/7087/paypal2o.jpg

I googled a lot which only left me even more confused.

I downloaded the PayPal PHP API from https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/library_download_sdks but don't know where to start and what to look for in the API.

I th开发者_如何转开发ink I need an absolute beginning guide, which I didn't find googling.

---

Take a look at this site https://www.paypal.com/cgi-bin/webscr?cmd=_pdn_xclick_techview_outside

That shoes you how to make a custom button, if you want to use a link though I think you need to use some JavaScript to make a link submit a form.