How to switch from Mac OS X to Linux

From ArticleWorld

Many people regard switching from OS X to Linux as somewhat useless. However, this is not what we are going to discuss here. Regardless of the reason why you want to do this (learning, job forces you to do so and so on), there are a few basic things you could try.

It is important to remember that Linux and OS X have some similarities, especially under the hood, but what Linux does not have is Aqua. Therefore:

Seven easy steps

1. Linux is not OS X. Therefore, be prepared for some things not to be too similar to OS X. In fact, be prepared to find a completely different desktop and completely new applications in most cases. Right now, there is no desktop environment to give you a familiar OS X environment by default, but you can customize KDE and Gnome to do so. You can do that to a high level, and, if you are using KDE applications, you can even use the OS X-style top menu bar, although it will only work with KDE applications.
2. KDE comes in handy through its ability to imitate the OS X desktop. Chances are it will be your best pick. Indeed, with some customization, you will be able to make it perform 99% like an OS X desktop.
3. Be prepared to know slightly more about your computer. OS X hides some concepts (like mounting or filesystem checking) under its user interface, but you may need to grasp some more knowledge. Learning advanced concepts is not required, but knowing what a shell is or what a window manager does will sometimes be helpful.
4. Take some familiar applications with you. Many applications you were using on OS X through X11 will also run on Linux. In fact, chances are they were built for Linux in the first place. Others have replicas. For example, Linux users liked Expose, so they wrote a few similar applications for Linux. Therefore, not all your knowledge will be left behind.
5. Keep some familiar concepts. For example, the filesystem hierarchy in Linux is quite similar to that of OS X. The technical knowledge you gain on Linux will often be helpful on OS X, and vice-versa.
6. Read, ask, try. It probably took you some time to master OS X well. Expect to need some time for Linux, too. Search the web, look through the documentation and search the forum where you are posting before asking. The open-source community is huge, and it is bound by the Internet, so there is a very high chance that someone got stuck in the same place before you. It may also help if you get a book, like O'Reilly's Linux in a Nutshell
7. If you were using AppleScript, you may be in some trouble: there is no such thing on Linux. Actually, do expect a somewhat looser integration between applications. Drag'n'drop may not always work as expected, and the only vague replacement for AppleScript is shell scripting. However, do expect more command-line tools to be available.