It's not hard at all to install Linux most of the time. You may have some issues with drivers but getting Linux installed and running is usually very easy.
I second Drew Dad's recommendation for both Ubuntu as well as trying the boot from CD option first so you can test it out without making any changes to your system.
If you decide you want to really use it as your main OS, I recommend dual booting over virtualization and you can set up your computer to dual boot with Windows pretty easily, here is Ubuntu's manual on doing it:
https://help.ubuntu.com/community/WindowsDualBoot
Seed wrote:(i can still use the windows os as well correct? or am I thinking wrong)
With dual-boot you can. I have one of my laptops running this way, after booting it asks me to select from the installed operating systems and I can either boot in to Windows or Linux.