Linux is a FREE operating system (PAID operating systems Windows - Mac)

99% of all computer users can find everything they need in Linux. Only a few specialized programs that run only in Windows or Mac, that you may need for work. Would be the only reason for not using Linux 100% of the time.

Most common Linux to switch from Windows or Mac to Linux, would be Ubuntu.

Ubuntu
When you download Ubuntu, there will be different versions. 32bit, 64bit, newest version supported for 18 months, new
version ( missing some bells & whistles) supported for 5 years.

Not to worry it will say which version does what.

You can download Ubuntu, run it off the CD (LIVE CD), to test and see if you like it. Then it will have an option to install it, on the Live CD Desktop. You will also be given the choice to install it next to windows. Then on start
up you have a choice of which to use.

It has everything you have in windows plus some:
internet browsers, firefox, chromium, opera, open office (libre office), video encoders, mp3 - music converters, video players, burning software, games (Steam), disk partitioning tools... Way to many things to write down
And if you don't see it, check for addon's there are thousands!

Take a Tour of Ubuntu
http://www.ubuntu.com/desktop/take-the-tour
Ubuntu home http://www.ubuntu.com/

Now for the downside:
If you are running raid (multiple hard drives combined for speed or safety)
99.99% of personal computers (includes mac PC's PC = Personal Computer) DO NOT RUN RAID
You can still install it, but I would only recommend that if you're a super geekThe problem is not Linux, the problem is the raid provider not giving the Linux community access to the driver files.

Next problem is Nvidia video cards, if you are running more then one card. SLI (2 video cards), TRI-SLI (3 video cards) or Quad SLI (4 video cards).
Again you will have driver problems. I wouldn't do it unless you're a super geekAgain the problem is Nvidia, not letting the Linux community have access to their drivers. But Nvidia is now offering Linux drivers (they don't work well with any SLI)

A list of easy to use Linux OS's that are very close to how Windows & Mac work. But of course MUCH better then either Windows or Mac!

Debian
The Debian Project is an association of individuals who have made common cause to create a free operating system. This operating system that we have created is called Debian.

An operating system is the set of basic programs and utilities that make your computer run. At the core of an operating system is the kernel. The kernel is the most fundamental program on the computer and does all the basic housekeeping and lets you start other programs.

Debian systems currently use the Linux kernel or the FreeBSD kernel. Linux is a piece of software started by Linus Torvalds and supported by thousands of programmers worldwide. FreeBSD is an operating system including a kernel and other software.

However, work is in progress to provide Debian for other kernels, primarily for the Hurd. The Hurd is a collection of servers that run on top of a microkernel (such as Mach) to implement different features. The Hurd is free software produced by the GNU project.

A large part of the basic tools that fill out the operating system come from the GNU project; hence the names: GNU/Linux, GNU/kFreeBSD, and GNU/Hurd. These tools are also free.

Of course, the thing that people want is application software: programs to help them get what they want to do done, from editing documents to running a business to playing games to writing more software. Debian comes with over 51000 packages (precompiled software that is bundled up in a nice format for easy installation on your machine), a package manager (APT), and other utilities that make it possible to manage thousands of packages on thousands of computers as easily as installing a single application. All of it free.

It's a bit like a tower. At the base is the kernel. On top of that are all the basic tools. Next is all the software that you run on the computer. At the top of the tower is Debian — carefully organizing and fitting everything so it all works together.
https://www.debian.org 

Mint based on Ubuntu
The purpose of Linux Mint is to produce a modern, elegant and comfortable operating system which is
both powerful and easy to use.

Started in 2006, Linux Mint is now the 4th most widely used home operating system behind Microsoft
Windows, Apple Mac OS and Canonical's Ubuntu.

Some of the reasons for the success of Linux Mint are:
It works out of the box, with full multimedia support and is extremely easy to use.
It's both free of cost and open source.
It's community-driven. Users are encouraged to send feedback to the project so that their
ideas can be used to improve Linux Mint.
Based on Debian and Ubuntu, it provides about 30,000 packages and one of the best software
managers.
It's safe and reliable. Thanks to a conservative approach to software updates, a unique
Update Manager and the robustness of its Linux architecture, Linux Mint requires very
little maintenance (no regressions, no antivirus, no anti-spyware...etc).
http://www.linuxmint.com 

Fedora
Fedora is a Linux-based operating system, a collection of software that makes your computer run. You can use Fedora in addition to, or instead of, other operating systems such as Microsoft Windows™ or Mac OS X™. The Fedora operating system is completely free of cost for you to enjoy and share.

The Fedora Project is the name of a worldwide community of people who love, use, and build free software. We want to lead in the creation and spread of free code and content by working together as a community. Fedora is sponsored by Red Hat, the world's most trusted provider of open source technology. Red Hat invests in Fedora to encourage collaboration and incubate innovative new free software technologies.
http://fedoraproject.org 

There are many different versions of Linux, most are free, secure and virus free

I guess that over 70% of the web sites you visit daily run on a Linux Server. Most of big businesses run Linux servers. All my websites including the Happy As Is server are running on Linux, The NEW server for Happy As Is will be running Centos 6.4 Linux

Some of the Linux downloads are very slow on their sites so I have added them to mine.
http://beast-usa.com/downloads/linux/linuxdownloads.html 
If you use Slimjet "Turbo Download" or a download manager for speed they should download around 9 MB/s!
Debian for one is a great OS but the download speed on their website is around 130 KB/s.

If you have questions or need help just ask!