Below you will find a number of links with useful information:

FAA - Field Approval Process 
The field approval process is used for one serial numbered aircraft in accordance with FAA Order 8900.1, Vol. 4, Chapter 9.
http://www.faa.gov/aircraft/air_cert/design_approvals/field_approvals/field_approv_proc/

Air Services Australia - Keeping safety first                                                              http://www.airservicesaustralia.com/

Civil Aviation Safety Authority of Australia 
http://www.casa.gov.au/

Jabiru Aircraft
Manufacturers of the famous Jabiru aircraft

Erie Aviation, Inc - USA
http://www.erieaviation.com/ 

Brant Aero - Canada
http://www.brantaero.com/ 

Air Sports TV
http://www.airsports.tv/ 

Aeroflex
http://www.aeroflex.com/

Euro Control - website with FAQ's that may be of interest:-
http://www.eurocontrol.int/corporate/public/subsite_homepage/index.html