In order to switch from one operating system to another it does take some time and effort. Over the passed roughly 6 months I've used Ubuntu as my primary OS. This is not as simple of a switch as you may think especially if you've been using Windows all your life. In the passed Linux was not very end-user friendly and sort of difficult to get into. Today, Ubuntu makes switching over extremely easy. By default it comes with almost all the software you really need in order to be productive. Getting things like music, videos, and other media to play doesn't take much effort either. It's all about planning ahead.
Check your hardware.
First thing you want to do is make sure your hardware is well supported in the Linux community. A few Google searches will let you know what you're up against. Most hardware does tend to work right out of the box with Ubuntu. Booting into the Live CD is a great way to check if you're too lazy to manually search. Once you're in the Live CD you can easily see if those essential pieces of hardware work like sound, wireless, ethernet, and video.
What do you need to do on a daily basis?
Make a list of applications you use daily. Include everything from IM clients to games. Once you have that list you can easily check the open source alternatives to see what you want. If you absolutely need a specific Windows application, WINE is the next best thing. It allows you to run Windows applications inside of Linux including many games, MS Office, and even Adobe Photoshop. Their site lists what works, what doesn't, and even tips on how to get things going. Even as a last resort, you can install VMWare or VirtualBox and run Windows itself inside a Virtual Machine.
Don't dual boot if you're serious about switching.
One thing I've learned, don't set up dual booting if you're serious about making the switch. I've tried to switch many times but have always used dual boot. I realized I was always booting to Windows instead of Linux and eventually would just lose interest. Halfway through my college career, being a Network Security student, I realized Linux was something I should seriously consider and now rarely use Windows.
To sum everything up, do your research. Doing research before making the switch will ensure you'll keep using Linux and not look back. If you blindly install Linux you'll find yourself wanting to go back to Windows and feel lost. Ubuntu has a great community base and people are always looking to help out. Just check out their forums or IRC channel (#ubuntu on freenode).