Tutorial [Q] [ULTA noob] So basically I need help with flashing my s2 gt-i9100

Hi all,
I recently just bought a used s2 really cheap, this is my first android phone (I had a windows phone previous to this one, dont laugh)
I would like to root it (but not install custom roms because the thought of that scares me) but I am a bit confused about the process. I have watched plenty of videos and read plenty of tutorials but its very confusing (to me anyway).
Just think of me as a tourist asking for directions.

so here is all the information i can give you about the phone:

-Model number: GT-I9100
-Android version: 4.1.2
-Baseband version: I9100XXMS2
-Kernel version: 3.0.31-1211311
dpi@DELL251 #3
SMP PREEMPT Thu May 16
10:05:20 KST 2013

-Build number: JZO54K.I9100XWLSW

Im fairly sure this phone was bought in Ireland (where I live) so would I need some sort of 'European' variant?
So all I need is someone to point me to which niknak I need to download to get me going, thanks in advance -Liam