Part One: What Linux Is Not
There are a lot of things being said about Linux that are not true. Some well-intentioned Linux fans sometimes try to paint Linux as perfect for everyone and that it will solve all your computing problems; this is a disservice to people considering Linux and to the Linux community because people may try Linux with unrealistic expectations and give up on it when they find out so many things they were told by "Linux Superfans" were untrue or misleading.
I'll cover some of the more common misconceptions about switching to Linux. These mostly apply to those switching from Microsoft Windows, but may apply to those switching from other operating systems, too:
Linux is better than whatever you're currently using. This is pure opinion. It is an opinion that I mostly agree with, but opinion none the less. There are plenty of things that Linux can do better than Windows that can be measured and proven, but just saying that Linux is better is misleading.
You'll never get hacked/viruses/trojans/spyware. While it is true that you are much less likely to get any of this junk running Linux, it is still a threat. Linux enjoys a great community of developers who make security a priority, file permissions, firewalls, and frequent updates combine to make Linux extremely secure.
Linux is as user friendly as Windows. This is misleading. Linux can be very user friendly, there are several Linux distributions that excel in being as new user friendly as possible (more on this in Part Three: Is SUSE the Right Distribution For Me?), but there are times when new Linux users will be confused and frustrated at why tasks that were painfully easy to do in Windows are now just painful to do in Linux.
New Linux users switching from Windows will sit down and try to do things the "Windows way", as you might
expect, this won't work and when it doesn't the person will become frustrated and say "Linux isn't user friendly". The person who will get frustrated the most will be the Windows "power user" because they will find themselves unable to move around Linux like they could with Windows. Learning Linux will take time, eventually you may find the "Linux way" of doing something to be much more efficient and/or secure than the way you are used to. When trying Linux for the first time and you get frustrated, ask yourself if you are frustrated because Linux isn't user friendly or because performing a given task in Linux is different than how it is done in Windows.
Linux is faster than Windows. Nope. Windows XP and SUSE seem to take about the same time to boot and perform most tasks. Opening many applications in Windows is often faster than opening a similar application in Linux is. This is for reasons that are beyond my ability to understand or explain in detail, however it comes down to this: Windows has several processes running in the background that make opening many applications faster. Most Linux distributions choose not to do this for security and stability reasons. You are, however able to legally modify your Linux installation to mimic Windows' action of partially loading an application in the background, but you will also be opening yourself up to those same security and stability issues.
It has been my experience (and from what I've read, the experience of others) that when under a heavy load Linux desktops and servers will respond much faster than their Windows counterparts. Just to be clear, Linux is not slow by any means, just don't switch to Linux expecting to be blown away with its blazing speed.
Linux is more stable. I'll agree that this is mostly true, but it can also be misleading. A lot of Linux software is made by small groups of people who consider it a hobby or their way to "give something back" to the Linux community. Because they don't have the resources or budget to test their product on all the possible hardware and software configurations and under all the possible usage conditions, most Linux developers depend on users to report bugs. For software that has been around for a while, this produces a rock-solid product that will be extremely stable under nearly any condition. However, for newer software that has not been "battle tested" on the countless configurations it will no doubt be used under, this extreme level of stability may not be there yet. If rock-solid stability is important to you, make sure you only install "battle tested" software on your Linux machine.
Microsoft Windows integrates many of the applications that run on it with the "core" of the operating
system, this is related to the speed with which applications open under Windows as discussed above. However, this also presents the problem of when an application crashes, it often brings down the whole OS with it (to be fair, I think this fault has been improved upon in XP); resulting in an ugly reboot with possible data loss, or hard drive corruption. Because Linux maintains a certain level of distance with each of the running processes, an application crash will often just mean you need to restart the application, rarely will it crash the whole system.
The few times I've had noticeable stability issues in Linux the problems can be traced back to things that can't be blamed on the OS: my laptop overheats (my laptop's fault), my piss-poor DirecWay ISP gets crazy (piss-poor DirecWay's fault), or I was using some new software (I knew there would be bugs when I installed it).
Linux has this emulator that runs all your Windows software. Sorry. Microsoft Office has been successfully ported to Linux using an emulator, so if you are unwilling to use any of the native Linux productivity suites, you can still use Office. The most popular windows emulator is called Wine. It is being used to run many popular windows programs with varying degrees of success. Of the programs that do work, some only "half-work" and plenty more don't work at all.
That said, nearly any application available for Windows has a counterpart available for Linux. Do a Google search for "whatever-application-you-are-curious-about Linux" and you are likely to find some information about what is available. If you find that there is no Linux counterpart for the Windows application that you have to be able to use in Linux in order for you to make the switch, Frank's Corner keeps track of what applications have been successfully used with Wine, which applications may never work, and some tips on how to to get it running.
Part Two: Making the Switch
Part Three: Is SUSE the Right Distribution For Me?