Now that you have a list of the files and directories that you need to back up, how do you get started? The first level, I would say, is to do a local backup. By this I mean backing up to another computer in your home, or to a backup server in your home, or to an external hard drive. This gives you some protection, but not enough to be a complete solution. As I mentioned previously, there are a lot of things that can wipe out your data and your backups (e.g. fire, flood, lightning, theft, etc.). But this does give you some protection, and depending on what hardware you already have on hand, may be completely free of charge.
What you want is something you can set up once, tell it what files and directories you want to back up, where you want the backup to go, and when to run the backup. After that you should not have to do anything except check your backups from time to time to make sure everything is still working properly. And the good news is that there are some excellent free solutions that will do just that. You can go searching on the Internet and find many options, but I will give you a few that will do the job.
In a Linux environment you could always run rsync in a script and call it with a cron task, but for anyone who is new to Linux and wants something simple I will give a couple of suggestions. fwbackups available as an RPM, and Back in Time, available as a DEB. Either one will give you a GUI interface, and do all of the things you need. I checked and Back in Time is in the Ubuntu repositories.
I really do not know much about Macintosh, it is not an environment that I find useful. I will mention two things, though. Macintosh has a program called Time Machine that is designed to work with an external hard drive to provide local backup. My guess is that this is the optimal solution, though it does cost money. However I will also point out that underneath the glossy surface of Macintosh OSX there is a Unix operating system, and many of the programs that work in Linux will work in Macintosh as well.
Again, I will give a couple of options here. One of the Linux programs mentioned above, fwbackups, is also available as a Windows *.exe file. But the one I have used and like is called Cobian Backup. The current version covers Windows NT, 2000, XP, 2003, Vista, but not Windows 7 yet. But it is being actively developed and I would not be surprised to see Windows 7 added fairly soon. As I write this a January 2010 Alpha release is planned for Cobian Backup 10.
So, for any platform you are on there is a backup solution that will let you easily set up an automated local backup to an external hard drive, a file server, or another computer on your network. So there really is no excuse not to do backups. But local backups are not sufficient. You will also need a remote solution, and that will be the next topic in this series.