Where to start?
Well Linux is great. What ever distribution that is. I'm sure you've researches this but the main distro of Linux is ubuntu. So I will be reffering to that a lot.
1. Good things:
Well every distribution I can think of is free! Free and open source (so it's easier for developers). In my opinion, a lit of distrobutions look nice, modern. Ubuntu is very easy to learn, and soo fast. Your computer could. Be 5 times faster.
2. Flaws:
Linux can be un-stable at times (much like windows). Some of it is based around a command line interface, but issues can be solved with a google search. Ubuntu uses unity for it's graphical user interface, this is terrible. Good news is you can switch to gnome! This will all become clear if you use Linux.
3. Data:
Well, this is where it gets complicated, so I'm gonna put it into 3 main points. A. Dual-boot B. Just Linux C. Restoring to windows.
A. Well, to start a dual boot allows you to choose between Linux and windows when booting. This is great, I use it. This is dependant on the Linux distribution though. Ubuntu in particular makes a dual hoot really easy, so no worries about backing up data, it will still be there. I cant really go into too much detail as I'm writing on an iPod touch, but I would recommend googling ubuntu and looking at their website. YouTube is also very, very helpful.
B. Just Linux, well you would need to back up your data and it would just be Linux, no windows.
C. Well, first if you have access to windows:
There is an app called mbrfix.exe download that read the instructions and give it a go. Then just delete the Linux partitions.
No access to windows:
Put a windows disc in or a restore disc and do a fresh install.
4. The verdict:
Cretantly give Linux a go, you may love it, you may hate it. Just backup your data. You will notice a speed increase (in Linux) as well as a whole new operating system to explore
Well, I hope I've helped, please send me a message if any help is needed.