Accept credit card payments without PayPal. Process transaction.

We already have been using paypal intgration in our Coldfusion coded site.

We now want to make the transition to let users input credit card info directly onto checkout on our site instead and we want to process the transaction.

What option are avilable? What components are involved? Any links available, tutorials. Is it very expensive, complicated.

Basically we want users to input the credit card # securely and in the background send to be processed and receive a return that it was ok to process an order

Thanks!