Advantages:
- Is not Windows, you can do what you want and is fully customizable and forget viruses, spywares, adwares... etc. All windows problems.
- Is OpenSource, that means, anyone can know how works, anyone can find and fix bugs.
- Is GNU, that means, you can download it, use it without restrictions, you are not forced to pay for use the software, on addition, if you want improve/add some functionality, you are forced to share this upgrade, that's good for the main developer, and rest of users. That improve Linux everyday, making it better and safe!
- You haven't limited versions of Linux, Ubuntu is ubuntu, Fedora is Fedora, OpenSuse is Opensuse... forget the Basic, Professional, Ultimate, Business versions...
- Linux is not one, is based on distributions, that means, you can choose the most comfortable for you, for ex., im a Gentoo user, i like modify and do optimizations to my Linux, but maybe you want some distribution like Ubuntu, Mandriva or Fedora, are very easy to use!
Disadvantages:
- Is not Windows (You must forget all your known software and games, Linux is not Windows, you can do the same, but is another software), but you can run Windows software/games with an application called Wine.
- Some professional software is not on Linux, like Adobe Photoshop, Avid, Autocad and other stuff, but you can find software with similar functionality and compatibility, like Gimp, Cinelerra, QCad and others...
- Exist multiple visual desktops, like Gnome, KDE, XFCE and you can confuse a bit... my recommendation: That's better, some distributions have better feeling with specific desktops, try Gnome, KDE (power desktops) and XFCE (light desktop based) and choose your most comfortable desktop.
- A recommendation of some friend on some distribution is not your best recommendation, my advice, only test it and choose!
Some distros to test it and some help:
- Ubuntu: Gnome desktop, usage: Easy, can fit it easy on a CD
- Mandriva: Gnome and KDE4 desktop, usage: Easy
- OpenSUSE: KDE4 desktop, usage: Middle Easy
- Fedora: Gnome desktop, usage: Easy