Greetings everyone

I come to you a complete noob to Linux, and over the next few months I will be building a computer for the very first time so I'm looking for suggestions on which distros to test.

This distro will need a GUI of some sort; partially because I need to get used to the Linux system, but also because this computer will probably see most of it's use coming out of my 4 1/2 yo daughter as well. So far my daughter is familiar enough with Windows XP to turn on the computer, find her user profile, and select her favorite programs from her desktop, so I'm looking more or less for something like that. My mother might also be using the computer from time to time, and her lack in computer smarts make a GUI important to her as well. The computer itself it going to be somewhat of a casual gamer's build so graphics support/etc. won't be much of an issue, and will most likely be primarily used to surf and stream videos off the web.

Any of the top 10 distributions will be fine. Take a look at the descriptions, and see which you are most interested in. Give a few a try. After all they're free and, for the most part, you can take them for a test drive without even installing them (LiveCD/USB).

Regarding the GUI there are several choices. The most popular desktops you can use are Gnome and KDE but there are a lot of others.

For a beginner I would recommend Mint or Mepis, both are very easy to use.

Okay, so I installed Ubundu alongside my Windows 7 (via diskboot) to give it a shot and... err... it broke my Windows O_O Had to restore my factory defaults to get it running again and now I'm looking for a way to remove Ubundu from my laptop completely. Thinking of trying Mint next... Are you able to install it alongside (or, even better, inside) Windows as well, or would I have to completely replace my OS?

you have a few options:
live-usb
dual-boot
wubi (i dont recommend)
virtual machine

most fairly recent distros will work with any method listed above (except wubi is ubuntu only).