e-commerce and e-books

[clvjr1]

Hello,
My name is Chuck. I am in the process of creating my own website with HTML. My site will be simple and not flashy. I want to use Pay-pal.

This is the way I hope to complete the site:
Main page - buy button - order page - order completion.

I need to know the following:

1) How to I create the download button for the customer to click after the purchase.
2) How to I store, or where do I keep the e-book. It is already pdf formatted.
3) Is there a specific code I need to write for this?

Thank you in advance for your help,

Chuck