This question is likely asked often. There are many reasons people might be asking it. They might not like Windows Vista and don't want to try Windows 7. They might not have enough money to spend on Windows or a Mac, but they want to be up-to-date with their operating system. They might just want to try something new.
The short answer to the question is only if you have extra time to spend on it. It is time consuming to learn a new operating system. I have off and on tried Ubuntu Linux (and a few others), I stopped using it for a while, but later I came back to it and learned even more. Usually to install a program it takes a few clicks and a small automatic download, but occasionally it won't be simple. In those circumstances the compressed file (.tar.bz2 usually) needs to be downloaded and compiled. For a beginner that can easily be a very hard task.
If you want to try it just to dip your foot in the pool and get a general idea what it's like, I suggest using a virtual machine. Just be warned all the eye candy is removed if you do that option. Another option is to use Wubi and install a dual boot without changing any partitions. If you want the eye candy and won't mind rebooting to get between Windows and Ubuntu, this is what I suggest. It will likely be slower than actually making a partition. If you plan on using Ubuntu a lot I suggest going with a full partition for it. Another option is installing it to a flash drive. That option is traditionally more for using it as a portable OS, but if you really want you can do it that way. The eye candy might or might not work. The last way I know of is using a live CD, this is more for recovery or just a small sample. None of your settings or programs will get saved if you do it this way.
I started using Ubuntu in a virtual machine a few years back. I was very annoyed at how slow it was and how unstable it seemed to be. I also was annoyed at the horrible graphics. A while later (before Wubi existed) I installed it on a separate partition. It was my first real experience with it, so I found it very confusing. I saw the YouTube videos showing how amazing Beryl/Compiz were. I tried installing Beryl, but I couldn't do it because I got this odd .tar.bz2 file and had no clue how to use it. I gave up and went back to Windows for a while again. I installed it on another partition again and tried getting the eye candy of Beryl/Compiz. This time I went through the package manager and installed almost everything that said Compiz. I rebooted (later I found ctrl+alt+backspace is faster) and found the options for Compiz. I did not know of any good applications that ran on Linux, so I couldn't use it a lot. So I went back to Windows yet again. A while later I used Wubi to install it. By this time I knew a lot more about it. I was able to find the package needed to install Compiz. I also found a program called Wine that will let me run some of my Windows applications on Linux. I used it quite a bit and decided to make a whole partition for it (Windows got corrupted, so I decided it was a good time to make the switch). I make a big compressed file (about 4 GB) of my whole Ubuntu drive. I downloaded the Ubuntu Server edition with only a command line so it would fit on my 650 MB CD. I extracted the backup file and fixed the boot loader and it was up and running just like before, but on a real partition now. Now I use it as my main OS; I do not know how long that will last though. I use Windows XP in a Virtual Box. The seamless mode is very useful for me.