Who should do this quest
Anyone who has data that they do not want to lose.
Do You Want to Lose Your Data?
If you have data that is on fewer than two devices then you are likely to lose it. One of the most dangerous practices that has somehow been encouraged is for people to keep data on a USB flash drive. If you keep data that you would like to keep on only a flash drive you are behaving foolishly. You should stop that practice immediately, if not sooner. The number of ways that you can lose those files is huge: physical loss, hardware failure, software corruption if you remove the drive without cleanly unmounting it.
Similarly, if all of your files are stored on your laptop’s hard drive and nowhere else, you are likely to lose all of your files. If you are content with being able to see just those photos that you uploaded to Facebook (and spending hours trying to find them all), then you should just keep doing what you are doing now.
When I was collecting data for my dissertation, I used my laptop as a file server where all of the files that students created were stored. A few weeks in to the study, my laptop’s hard drive failed. Because I backed my laptop up to my desktop every time I connected to the internet, replacing the hard drive in my laptop was one of the least disruptive unexpected problems I had with that study. (I pushed the files from my desktop at Stanford to my server at Vanderbilt daily, so in the event of an EMP on the West Coast, my data would still be safe.
The set of scripts that I used were a bit complicated and counted on my university giving my desktop a public IP address (a luxury that I have no longer). Fortunately, now there are many easy ways to keep you data backed up.
All of your data should be in one place
First: All of your data that you want to keep should be on the hard drive of your primary computer. Hard drives are huge now. As a rule, the first thing you should do when you get a new computer is to copy all of your files from the old one to the new one. (Exception: We are in a time when mass storage devices are going from one slow and cheap technology, hard drives, to a dramatically faster, but more expensive technology, solid state drives. If you bought, for example, a 128GB MacBook Air, the bulk of your music might need to be on some other device.)
Again: Every file that you have ever created should be on your hard drive. It takes more energy to decide which files to keep than to just keep them all. Any files that you leave on some old computer without copying to your new one will be lost when it dies, you give it away, or lose it in a fire.
What to back up
There are two kinds of data on your computer, data files, and program files. The data files are the files that you create, like papers that you write with your word processor or photos that you take. The program files are the computer operating system and all of your applications like Microsoft Office and the GIMP.
When you lose your data files, they are gone for good. You will never re-write those papers. Those photographs of your kitty, no matter how adorable will just be gone. You really, really, really want to back up things that you created. No amount of money can get them back.
When you lose your program files, the results are somewhat less tragic. You can re-install the operating system and all of those programs again. You put those CDs (if you got them) in a safe place, and downloading the other ones and finding the authorization keys is easy, right? It takes someone like me the better part of a day to install Windows and the various applications that one needs. You want to avoid doing that if at all possible. For most people, it is easier to just buy a new computer than to figure out how to re-install everything. If you lose these files, it is a bummer, but if you don’t mind shelling out of a new computer and spending a day setting it up, it’s not that big a deal.
Quick, Easy: Dropbox or Google Drive
The simplest thing to do is to put all of your files in Dropbox or Google Drive, and install their software, which automatically copies your files to their servers (when you are connected to the internet), and will even synchronize those files between all of your devices. If you use more than one computer, you really want to do this. Having access to your computer files on your phone is also a pretty handy thing.
If you have more than 2GB of files (and you do) Dropbox will cost you $100/year or $120/year if you pay by the month for a whole terabyte of data. You almost certainly do not have more than a terabyte of data. Google drive gives you 15GB for free (and I think that if you use your USA address, it may be more than 15GB). 15GB is enough for every file you have typed, probably every picture you have taken, but probably not all of your music (unless all of your music is already in the cloud).
With either of these solutions, you will want to change the location of your “My Documents” folder in Windows (and probably your Pictures and so on). To find out how to do that you type "change windows documents folder" into your favorite search engine and follow the directions. Similarly, Mac users should figure out how to convince Mac OS to put their files in the right place too. A similar Google search will yield a solution like this.
Easy. Cheap. Automatic.
If you have to download all of your data, it could take days to get it back over a slow (e.g., DSL) internet connection.
This does not back up your program files. If your hard dive dies, you probably do not have what it takes to rebuild your system.
This solution will see that all of your files (that will fit in the space allotted) are backed up. If your hard drive dies, you can get your files back. Depending on the amount of data you have and the speed of your internet connection, though, getting your data back might take several hours, or several days.
If you want to save your whole hard drive, and not just your data files, you need special software that gives you the ability to write everything to your hard drive. This is a chicken-egg problem. If your hard drive is dead and your computer will not boot, having your files on Dropbox is little help. You will need a program that provides a way to boot your computer without a functioning hard drive, download the data, and write it to the hard drive so that it will boot again.
If that sounds appealing to you, or you would like to understand it better, then you should find out more about that. A good place to look is The Wire Cutter. These services cost in the range of $50-$100/year.
Automatic. Easy. Will get your through a hard drive failure.
Inconvenient if you have a slow internet connection.
Backup to external hard drive
Both Windows and Mac come with software that will automatically back up your computer to an external hard drive. The only catch, after you get it set up, is to remember to plug the hard drive in. If you are a Normal Person with a laptop, you probably will not remember. If you have a desktop, then this is a pretty good solution, as you just leave the external drive plugged in to your computer all the time. External hard drives cost in range of $100-$150. Even if you do not manage to plug the hard drive in all the time, if you have set it up initially, you can probably recover from a complete hard drive failure for the cost of a new hard drive, which is considerably cheaper than a new computer.
Backup to a local file server
A hybrid solution is to get a Network Attached Storage device (NAS). This solution has most of the advantages of an external hard drive without having to remember to plug it in. This solution is much more expensive, though. It will run you about $500. This is probably not what most people want to do. It is what I do. (Except rather than getting a pre-built NAS, I bought a computer with 4 hard drive bays and set it up as a server.)
If you think this solution may be for you, check out this review from The Wire Cutter: Best NAS for Most Home Users. Here also is their treatise on making backups. You should probably read that, as it provides a much more complete and up-to-date version of what I wrote above.