eCommerce

I need to set up e-commerce sites. I want to use Paypal and seamlessly integrate it into the design (so you don't go to paypal website). I understand this is done by making the buy or add buttons process a form. If it really is this easy, and simply a case of attaching a piece of code to the buttons, could you tell me how it's done, and if there are any sites out there that give you this info and code.

Thanks.

Do you tell your customers you know how to do this, then attempt to have others (read: us) teach you how?

No, I've got my own stores I want to set up, and i just want to know how to make it seamless.

PayPal have a guide, read it

You must sign up in paypal with the business account, and they will give you the business tools, such as the paypal button, etc...

Paypal payments are not seamless... In my experience, Paypal does not give you enough control over the payment pages so you can customize to a point where the visitor doesn't know he;s left your site.

If you're in the UK, and you want to do some serious e-commerce'ing then Worldpay is your best option, and very easy to use.

As to how you integrate with Payal, that's completely down to how your system works.
I've had to integrate my CMS with Paypal and Worldpay, and I'd recommend reading their integration guides thoroughly, twice. Pick out the must have and get the basic information swapping working...
Just go form there...