Information from Software Update.
The 10.5.4 Update is recommended for all users running Mac OS X Leopard and includes general operating system fixes that enhance the stability, compatibility and security of your Mac.
For detailed information on this update, visit http://support.apple.com/kb/HT1994.
For detailed information on security updates, visit http://support.apple.com/kb/HT1222.
There needs to be a relatively small but comprehensive book on “INSIDE” Time Machine. It is very difficult to know what can be done, for a quick example, with material on the external drive that will never be wanted. How should be be deleted, etc. LOTS of questions in this vein but Apple hasn’t troubled itself to help us guys out here in the wilderness to know how best to make full use of this new and good tool.