Setting Up Credit Card Payments for AR Invoices v8.03

We are looking at setting up some AR Invoice to be paid by certain
customers with a credit card. Do I need to start process servers for
this? If so, what/how should they setup? Do we need any 3rd party
software ie: verisign ect? I am a complete newbie with this phase!
I am looking for other organizations experiences of do's and don'ts.
Any suggestions, guidance would be greatly appreciated.

Thank you

-Joe