GA Cross Domain Tracking

Greetings,

I am trying to setup cross domain google analytics reporting to track my conversation across the two domains using a FORM.

I have tried following Google’s guidelines but I believe its somewhat incomplete.

Is anyone able to direct me to an article that will explain everything from step A - Z, in particular:

(1) What code to install on the main domain
(2) What code to install the alternative domain that will have the form
(3) Should I do anything with the onsubmit event on the form for (2) ?

Thank you in advance for helping me figure it out,

Alexander