When you've opened the link to the
Kindle Developer's Corner, you can search for certificate information. The Snapshots of NiLuJe's hacks thread has quite a bit of information but start at the end and work your way back. A couple of short recent threads are Can't launch KUAL - any help for a tech disaster? and KUAL not launching on Kindle 4 Non-Touch (fw 4.0.1) after jailbreak – need help.