I posted the first step - mailing the application - in the Columbus thread. I hope my case is simple - there's nothing in my application that needs to be explained apart from a no-insurance traffic ticket from 1991 (aged 17) that I don't have a court record for. I only have 5 absenses since becoming LPR and those total 50 days. My criminal record is clean and I filed for Selective Service when I arrive, always filed taxes as Married, resident, never tried to vote etc.
I told them about the ticket during my k1 interview in London and my GreenCard interview in Columbus, and they didn't care in the least. Still, Ducks in a Row...
Funny story: (Wasn't funny to me at the time) When I went to the US Embassy in London for my K1 issuance I took my forms etc but had no copy of the court record for my ticket. I didn't think it was needed because the question was "Have you ever been convicted of a Crime or Offense?" then followed by "If you have been convicted of a Crime then please supply the court records." A traffic ticket is an "Offense" not a "Crime". So I checked the box for Yes and write down the details of the ticket, but didn't bring the court record as it wasn't a Crime.
When I stood in front of the officer for the interview she asked me for the court record for my 'Crime' and I tried to explain to her about it no being a crime etc. She get really testy with me and finally grabbed a red sharpie and wrong "No Court Record" across my application. "Please sit down and my supervisor will be out to explain it to you in a minute."
After 30 mins the supervisor came out and swore me in again before asking for the court record of my crime. I said "It was just a traffic ticket! I paid by mail! There is was no court heard, therefore no court record." Then she said; "I don't care about the traffic ticket, I want to knwo about this crime." "There was no crime! The other officer thinks the traffic ticket counts as a crime!" She looked shocked for a moment and said; "Is that it, just a traffic ticket? Heck, we don't care about traffic tickets!". She approved the application and I was stateside with fiancee my 31 days later. (our next anniversary is our 9th... )