The Firebird install process will create a new user: firebird. This is for added security. Please don't delete this user. The installer creates a Firebird framework in /Library/Frameworks. By default the install creates one super-user database user "SYSDBA" with a password "masterkey". You should change that password using gsec or isql according to the documentation.
The release notes can be found in the doc directory. More generic documentation for Firebird can be found on www.firebirdsql.org and the IBPhoenix web site at www.ibphoenix.com. There is also a yahoo group that can be subscribed to named "ib-support" if you have any problems.
