When I was a computer newbie, what I heard repeatedly was "The Number One Rule Of Computing is Make A Backup!" I've been working on an extended list beyond one item in order to help newer newbies consider further aspects of their computer experience that can help save them in a crisis. I don't consider my list definitive or even finished. But I like the list enough to publish it as a starting guide. So here I go:
The Rules Of Computing
1) Make a backup. Have two backup strategies. One strategy regularly backs up your crucial data to local external media away from your computer. The other strategy backup up this same data to an off-site location, such as in 'the cloud' or onto external media you take to a separate location each day. The idea is to have an off-site backup in case your computer site burns to the ground. Backups are also your first and best defense against malware damage and hardware failures. If you don't back up your data, you get what you deserve.
2) Verify all software before installing it. Verify your software source is reliable and that the software itself is reliable. Look up the software title on the Internet using a search engine to discover if it has been reported as problematic. Download software from reliable sources such as VersionTracker, MacUpdate, Major Geeks, etc. Don’t ever blindly install emailed software. It could be malware.
4) Keep your computer up-to-date with the most recent security updates. Apple provide security updates on a regular basis. Security Preferences, built into Mac OS X, should let you know when an update is available. You can also open Security Preferences yourself and have it check for you.
5) Use a 'Standard' account when surfing the Internet or using your Mac on any network. Do NOT use an 'Administrator' account in these situations. This is not a cure all to prevent your Mac from becoming hacked or malware infected. But it adds a terrific layer of security to help prevent malicious root access to your computer.
6) Password protect your user account. Make sure your account password is not a dictionary word or you'll be hacked in no time flat. Use something long and obscure that you can remember but that you expect no one could guess. To this day I run into people who tell me 'But I'm the only one who uses my computer!'. Cure your ignorance please. There is NO excuse for not protecting your computer with a password. If you don't protect your user account, you get what you deserve.
Yes, I'm that mean and cruel when it comes to computer security. There are wonderful security strategies and tools that Apple provide, such as Time Machine, Disk Utility, Standard user accounts and password protection. If you don't put them to use, I have no sympathy! If you have questions about how to make them work for you, write to me, talk to Mac users you know, contact users on the Internet or at your local Mac user group. These tools are not difficult. They are important and they are FREE.
A Few Further Strategies:
I'm only going to list these strategies as they are more complicated and involved to install and get running. What's important is that they are available, they are also FREE, and they may well save you from giving away data to the bad guys.
A) FileVault. You will find it inside the Security System Preferences. It lets you transparently encrypt your entire user account folder so no one can ever get to your data without knowing the decryption password. This is rock solid encryption you can rely upon. Apple will be providing an option for encrypting your ENTIRE computer hard drive in Mac OS X 10.7 Lion. I personally consider whold drive encryption to be overkill. But it is considered to be critical in Enterprise business situations. Note that there are some minor dysfunctions that result from encrypting your user account. But if you have critical data, it is an excellent security tool.
B) Firmware Password. Apple provide a utility to set their Firmware Password Utility on all Mac OS X installation DVDs. It adds another layer of security to keep the bad guys out of your computer. Sadly, it is not fool proof. A tech savvy bad guy can work around it. Encryption is a much more effective tool. Also note that you lose some minor computer functionality when you use a firmware password.
C) GnuPG, aka GNU Privacy Guard. I have been using GPG for many years at this point. I'm a fairly infamous critic of the bugs that have should up in the related tools from time to time. Also note that GnuPG has a steep learning curve and can be a bit frustrating. However, it is a FREE and brilliant tool with many users. You can encrypt and password protect anything you like. The Apple Mail tool lets you digitally sign all your email in order to verify exactly who you are to those who receive your email. You can encrypt your email such that no one can read it in transit over the Internet. It lets you create any number of encryption keys as well as collect public keys from your friends and acquaintances. And more! If you want to be serious about encryption, GPG is excellent. These days it also has a terrific group of developers dedicated to keeping it bug free and up-to-date.
D) Disk Utility. Among the many features of the Mac OS X Disk Utility application is the ability to create encrypted, password protected .sparseimage files. I absolutely love this feature and use a sparseimage I created all day, every day. I have my sparseimage open every time I log into my user account. I provide the decryption password and it sits on my desktop like a disk volume. Anything I put into it is encrypted and unavailable to anyone but me as soon as I close the disk image. Because its a sparseimage, it can grow to as large a size as you choose as you add more into it. Recently the DropBox application and server have become notorious because nothing-at-all is encrypted when you use it. That can be very bad. However, I work around this problem by putting only my sparseimage file into my drop box. No one has any access to anything I have in my DropBox ever, thanks to this great tool.
E) Anti-Malware applications. I own, use and love Intego's VirusBarrier X6 ($50). There aren't any better anti-malware applications, period. But I have to pay for malware signatures every year. If you are a professional user, VirusBarrier is well worth the cost.
If you're a casual computer user, paying for anti-malware is a bit less critical. I've worked fairly closely with Mark Allan and friends who develop and support the FREE program ClamXav. There was a time when I had quite the run-in with the ClamAV Open Source project because most volunteers there cared not-a-whit about Mac OS X. But gradually Mark and I managed to turn a few heads and encourage them to get up-to-date with current Mac malware. At this point in time I can tell you that just about all current Mac malware is being detected by ClamAV. Therefore, I highly recommend downloading, installing and running ClamXav from time to time if you are concerned about malware. The GUI Mark provides is excellent.
Also, if you own Snow Leopard Cache Cleaner ($15) you will find that it includes its own implementation of ClamAV, also highly recommended. I no longer recommend free iAntiVirus as it is now out-of-date and less effective than the ClamAV alternatives.
There are plenty more security tools and strategies, both free and for a fee. But the above is a good start with reasonable coverage.
For the extra security conscious, as ever I highly recommend the TWiT.tv podcast 'Security Now' with the most excellent Steve Gibson. It gets highly technical but is wonderfully presented and very contemporary. You can look up the podcast in iTunes or visit its dedicated webpage at: