Once you figure out the basics, check out the new free security guides published by the National Security Agency (NSA).
All operating systems are go
Unlike me, the NSA does not favor a certain operating system—it has published guides for Windows, OS X, Linux, and even Sun Solaris.
In general, the guides are outstanding. They are concise, clear, and provide countless easy steps to help improve your computer’s security. Considering the source, I would highly recommend following their tips.
The NSA has also published a variety of guides related to peripherals—like wireless routers—with suggested ways of setting up your wireless router to increase security.
Good summary of tips in one place
The security hardening guide for Mac OS X 10.6 contains a number of tips that I already knew and many of which have been published in various Lawyerist posts. The advantage to the NSA’s guide, however, is that all of the tips are in one place—a two-page guide that lays out everything clearly.
The guide also takes a number of steps to the next level. For example, most users can disable their Bluetooth and iSight cameras by simply turning them off in System Preferences. Turning them off does not guarantee a rogue program will not access them and leave your computer open to security issues.
Fortunately, the NSA guide provides clear and quick directions for how to permanently disable those features (although I didn’t notice any instructions on how to get them working again). Keep that in mind when following the guide—you might turn something off without knowing how to turn it back on.
While many of the security tips may seem extreme, you should at least read over the guide for your operating system so you understand the potential risks and decide if you are willing to live with them.