Overall a Linux based platform can perform most of the tasks equally as well as a propietary platform using the likes of Ubuntu and its derivative distros. However Linux does have its limitations with some applications and in particular gaming. For example I retain a Windows partition to run specific applications such as Office 2010 etc.
Due to probability you would want to continue to run Windows applications I would suggest either Dual Booting Linux with Windows or installing Linux inside Windows (as described in the next paragraph)
http://apcmag.com/how_to_dual_boot_windows_xp_and_linux_xp_installed_first.htm
http://apcmag.com/how_to_dualboot_vista_with_linux_vista_installed_first.htm
I thoroughly recommend Linux Mint 9 LTS and Linux Mint 10 Main Edition which are built upon Ubuntu 10.04 LTS and Ubuntu 10.10 they are easy to install and easy to use plus they come with much of the software you are likely to need preinstalled
Installing Linux as a dual-boot with Windows without partitioning
http://psychocats.net/ubuntu/wubi
Linux Mint has a similar installer called mint4win (mint4win works the same as the Ubuntu Windows installer so the instructions outlined above are almost identical)
You keep Windows as it is, mint4win only adds an extra option to boot into Linux Mint. mint4win 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.
mint4win 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 Linux Mint LiveCD and you will offered the option of installing inside windows which is where the mint4win installer comes in, you will be asked how many gigabytes you wish to allocate to Linux Mint (I recommend 8gb) then you set a password for your installation then click install and thats it.
Once Linux Mint is fully installed upon starting your PC you will be given a choice of which operating system you want to use Windows or Linux Mint
Linux Mint 9 LTS Download
http://www.linuxmint.com/edition.php?id=52
Linux Mint 10 Download
http://www.linuxmint.com/edition.php?id=67
Linux Mint 9 LTS User Guide
http://www.linuxmint.com/rel_isadora.php
Linux Mint 10 User Guide
http://linuxmint.com/rel_julia.php
You download the ISO. image of Linux Mint 9 LTS or Linux Mint 10 then you need to create a Bootable LiveCD for installation
https://help.ubuntu.com/community/BurningIsoHowto
Linux Mint 9 LTS and Linux Mint 10 can also be run straight from the LiveCD from Boot without touching your Hard Drive
LUg.