E-Commerce under Apache

Continuing our Q&A into Apache and SSL, we received the below. I'm sure people have ideas and comments. After all, Amazon can do it :):
conraduno writes "I am a professional web developer and I was recently approached to develop an e-commerce based commercial site. I have never dealt with e-commerce before, and while I have extensive knowledge of order entry systems I have never before dealt with online credit card entry. My question is this: What do I need to develop secure, online credit card based order form, that is scaleable but at the exact same time simple. I have done a little research on SSL, and I am wondering if there are any other viable alternatives, and if not, what do I need to set up an SSL based transaction? "