It is still early for beginning any of the registration procedures but I picked up EAA's Amateur-Built Certification Kit just to review the procedures and paperwork. The kit EAA has put together including the forms and step by step procedures look like an excellent idea. There are a number of forms and tasks to complete in preparing for the final aircraft inspection. Without such a guide it would be easy to miss something and fail the initial inspection on paperwork grounds alone.
By the way, the kit also includes an experimental decal, a sheet of common labels and placards, and a data plate for the tail cone of the aircraft. I have already acquired an alternative data plate from Van's Air Force.
