The IARU provides a frequency coordination service for satellites proposing to operate in the Amateur-satellite Service allocations such as 145.8-146 and 435-438 MHz.
Contact email addresses, an application form, and ITU tutorial are available at http://www.iaru.org/satellite.html
The status of current applications can be seen at http://www.amsat.org.uk/iaru
ITU Radiocommunication Bureau Registration Tutorial for potential amateur satellite builders