OS X includes a number of tools that can be useful for troubleshooting purposes. Console, which you’ll find in the Applications -> Utilities folder, is one such tool. Console is a front-end for all the various log files created by both OS X itself and the programs you use with the system. Depending on how the program (or portion of the system) was developed, log entries can be generated for everything from the routine (Disk Utility reporting on a CD-R burn) to the far from routine (CrashReporter entries are generated whenever a program unexpectedly quits).
In addition to displaying the system-wide system.log file, Console displays log files in three folders: your user’s Logs folder, the top-level Library/Logs folder, and the system-owned /var/log folder. There can be a lot of files in these folders—on my Mac Pro, for instance, there are nearly 100 different log files. So using Console as a troubleshooting tool can be a bit intimidating, as you’ll be digging through that huge list of logs to find the one you want to see. But if you’re running 10.5, there’s a little trick you can use to make it much easier to browse certain log files.
Launch Console, and make sure the list of logs is visible in the leftmost column—click the button labeled Show Log List in the toolbar if it’s not. Next, find the log file you’d like to keep an eye on, and just drag it to the Finder. This will create an alias to that log file, which you can then directly open with a double-click. Put it in the Dock, the Sidebar, or the Toolbar for extra-quick access. Even better, though, is that you can use Quick Look on these log files, to easily check their contents without even opening Console—you will, though, have to scroll to the bottom of the log file to see the newest entries.
I use this trick to keep aliases to the system log (system.log in the LOG FILES section), install.log (which tracks things such as Software Update reports and the results of permission repairs), and mail.log, which can be useful for debugging issues with Mail.
Note that not all log files will open in Console when double-clicked, nor will they work with Quick Look. In general, if the filename in the log list ends in .log, then this trick will work. Other files, such as the CUPS access_log file, will still turn into aliases when dragged. However, when opening those aliases, the log file will open in TextEdit, and Quick Look won’t work. You shouldn’t run into this problem with .log files, however.