One of the difficulties of switching from one OS to the other is trying to locate all the system files and keep track of where the new OS stores all its settings.
The image above, which you can also view at its original resolution, is a complete Linux File System map that's quite helpful for newbies like myself. I'm not sure what specific distribution this layout is from and, depending on the system you're using, your actual structure may vary, with directories left out or additional ones present, but the basic outline should be the same.
I've recently installed Ubuntu on my laptop and have occasionally had some trouble figuring out where things are or where new files ought to go (for instance, fonts on Ubuntu live in ~/.Fonts, something that took me a while to figure out).
With Linux in particular it can be difficult if you're used to Mac OS X. Although OS X is based on Unix, it stores some system files in very non-*nix locations, which can trip you up when you're using Linux.
For those who prefer a horizontal graph, I also dug up this page, which has a similar diagram about three quarters of the way down the page.
[via Digg]
