Landing page confusion

I have looked through the warrior forum about this but couldn't find what i was looking for.

Now I know with cpa offers you can either direct link using the redirect or the iframe code to send visitors straight to the merchants offer through your aff link, which is simple enough. But its the landing page thing I'm not so sure about.

If say I was promoting a credit card offer, would i make the landing page to look and act similar to the merchants landing page? if so what do i then do once the visitor has filled in the required fields?

do I setup the landing page to send the details they filled in to me and then do i input the very same details that i received from them onto the merchants form and submit that myself?

Or do I, once the visitor has input his/her details into the form direct them to the merchants page? if so then that would mean they will have to put in the same details twice? Not good surely?

I have been accepted by a few networks and want to get started but before i can start testing I want to be clear that I fully understand the processes involved.

Sorry if this seems a newbie ish to you guys but, if you don't ask questions you won't know the answers.

Cheers

mike