How would Linux and Windows work together

How would Linux and Windows work together?

To install ubuntu linux, you download the cd image from the site and burn it, or if you have a slow connection you can order the cd for free from shipit. when you install ubuntu, it will partition your drive and create what is known as a dual-boot system. then when you start up your computer there will be a text menu (known as the grub boot menu) asking which operating system you would like to use, if you dont answer within a certain time it loads the default. so yes you can select which one starts on your computer.
Ubuntu is free. I would say it is safer than xp because there are fewer viruses for it and nothing can install without your permission. The firewalls are harder to configure than windows firewall in my opinion. Overall it is a very good system to run. My favorite part is that it keeps all of your software up to date that you install from the repositories, Like in windows update when you download the patches for the operating system, only ubuntu does it for the os and all the programs, which is more secure.
Give it a try, and google for help if you need it.