The first thing that you will have to do (as the US citizen spouse) is file the I-130. In order to file for a K-3 you will need to show that you have filed the I-130 already by providing a receipt notice for the I-130.
File the K-3
The K-3 visa should be filed using form I129F along with the following documents:
Evidence of the marraige (mairraige certificate, pictures, BC for kids if applicable, etc...).
If the Beneficiary has criminal records then all court dispostions, ajudications etc...should be submitted witht he K-3 visa package at this time.
Also a copy of the I-130 reciept notice should be included witht he K-3 visa package.
If marraige was entered into abroad/next step.
The beneficiary will have to go to the inteview in the country where the marraige was entered into. Once the beneficiary has had clearence...the case will be passed on the the consulate with jurisdiction...and the beneficiary will be sent "packet 3" describing what documents are necessary for the Beneficiary to collect as well as where the benenficiary should go to have their medical exam done.
If K-3 is granted
if the K-3 visa is granted the beneficiary could enter the US with such and await the Service's decision on the underlying I-130 next to thier US citizen spouse. the K-3 visa holder will be able to apply for a EAD card while awaiting the I-130 decision. If the I-130 is denied the K-3 visa holder will have 30 days to departure the US back to their country before such visa expires (along with any underlying EAD cards). the K-3 visa holder will ONLY be able to adjust their status to that of permenant resident through the marraige petition of the US citizen that originally claimed the K-3 visa on their behalf.