So you've got a bunch of files on your hard disk, and you want to burn them to a CD. You can stick in a blank CD and trust to Window's built-in file burning utility to do it, or you can get a specific program to help you. One such is Astroburn Lite, the freeware version of Astroburn.
Astroburn Lite is... light. While some programs present a simple front end and then reveal depth as you drill through option and setting dialogs, Astroburn Lite is pretty much "What You See Is What You Get." The only "Options" are the language (and there's a huge list) and the visual skin, and your only real choice of operations is "Burn files" or "Burn a .iso image".
Using Astroburn Lite is simple. You can either select files manually (you can Ctrl-click in the dialog box to select multiple files and folders in one go) or you can drag-and-drop files and folders into the window. You can also rearrange and rename what you've dragged, so your burned disk does not have to have the same structure as your source data. Once you're happy with the layout, you simply hit "Start Burn," and it's off! It can burn any file type on your hard drive to writeable CDs, DVD, or Blu-Ray disks.
It's a good thing Astroburn Lite is so simple, because the "Help" function takes you to a Web site which contains the help for the full Astroburn program, which has a somewhat different interface. The help page is also heavily bedecked with advertising, though fortunately not to the point where it's impossible to read the actual help.
That's pretty much it. If your burning needs are either infrequent, or simply very straightforward, Astroburn Lite will do the job with simplicity. It also burns to Blu-Ray, a feature lacking in many other free programs, such as DeepBurner Free.
Note: Astroburn Lite's installer will ask if you want to install their browser toolbar, change your default search engine, or change your home page. These are all selected by default; odds are good you will want to deselect them.