Why Linux is Better
http://www.whylinuxisbetter.net/
Here are some options for installing or trying out Linux
Option One (Full installation)
I thoroughly recommend Linux Mint 8 Main Edition which is built upon Ubuntu 9.10 Its easy to install and easy to use plus it comes with much of the software you are likely to need preinstalled
Linux Mint 8 Download
http://www.linuxmint.com/edition.php?id=44
The Perfect Desktop - Linux Mint 8 (Helena) Installation
http://www.howtoforge.com/the-perfect-desktop-linux-mint-8-helena
Linux Mint 8 Helena User Guide
http://www.scribd.com/doc/23787138/Linux-Mint-8-Helena-User-Guide
You download the ISO. image of Linux Mint 8 then you need to create a Bootable LiveCD for installation
Linux Mint 8 can also be run direct from the LiveCD from Booting up without touching your Hard Drive
Option Two (Install Linux inside Windows)
Installing Ubuntu as a dual-boot with Windows without partitioning
http://www.psychocats.net/ubuntu/wubi
You keep Windows as it is, Wubi only adds an extra option to boot into Ubuntu. Wubi does not require you to modify the partitions of your PC, or to use a different bootloader, and does not install special drivers. It works just like any other application.
Wubi keeps most of the files in one folder, and if you do not like it, you can simply uninstall it as any other application.
Boot in to windows insert the Ubuntu 9.10 LiveCD and you will offered the option of installing inside windows which is where the Wubi installer comes in, you will be asked how many gigabytes you wish to allocate to Ubuntu (I recommend 8gb) then you set a password for your installation then click install and thats it.
Once Ubuntu is fully installed upon starting your PC you will be given a choice of which operating system you want to use Windows or Ubuntu
Ubuntu 9.10 Download
http://releases.ubuntu.com/9.10/
Ubuntu 9.10 (Karmic Koala) User Guide
http://ubuntuguide.org/wiki/Ubuntu:Karmic
Linux Mint 7 has a similar feature called mint4win and the directions given above for Wubi can be followed (XP and Vista only)
http://duncsweb.com/2009/09/27/mint4win-a-wubi-based-installer-of-linux-mint/
Linux Mint 7 Download
http://www.linuxmint.com/edition.php?id=38
Linux Mint 7 Gloria User Guide
http://www.scribd.com/doc/15884753/Linux-Mint-7-Gloria-User-Guide
Ubuntu 9.10 and Linux Mint 7 can also be run straight from the LiveCD without touching your Hard drive
At present I do not recommend Ubuntu 10.04/Linux Mint 9 owing to multiple stability issues
Option Three (LiveCD)
Here the possibilities are endless as you can try out as many different Linux distros. until you find the one thats right for you DISTROWATCH.COM gives full listings (second lists the major distributions)
http://distrowatch.com/
Major Linux Distributions
http://distrowatch.com/dwres.php?resource=major
Linux and Windows applications
In most cases native open source alternatives are available and can be installed using the Ubuntu Software Center
Installing Software in Ubuntu
http://www.psychocats.net/ubuntu/installingsoftware
If you want to run a specific Windows app. then WINE which is a Windows Compatability Layer is a possibility however this method should not be relied upon
Using Wine on Ubuntu
http://www.psychocats.net/ubuntu/wine
Here is a list of Windows apps. which will run on WINE
Wine Application Database (AppDB)
http://appdb.winehq.org/
A better solution would be to grab a copy of XP and install it on a virtual machine. I thoroughly recommend VirtualBox which is easy to use and incredibly versatile
VirtualBox is available in the Ubuntu Software Center as outlined earlier in my answer
Installing Windows XP as a virtual machine on VirtualBox
http://www.ghacks.net/2009/06/15/installing-a-windows-xp-as-a-virtual-machine-on-virtualbox/
XP performance on a virtual machine is quite acceptable based on allocating 1gb RAM and 128mb Graphics
Install VirtualBox Guest Additions as well which wll give you additional features
Install Guest Additions for a better VirtualBox experience
http://www.ghacks.net/2009/06/17/install-guest-additions-for-a-better-virtualbox-experience/
If you rely on Windows applications heavily then (Option 2) would be best
LUg.