Rooting your android phone (Samsung)

To root first of all:
1) Do it after your warranty period.
2) Do it at your own risk.
3) If any problem after rooting contact me.

Download update.zip from this link according to your model:

Samsung Galaxy Y
http://adf.ly/5NZMS

Samsung Galaxy Ace
http://stickycover.com/downloads

Samsung Galaxy S2
http://forum.xda-developers.com/showthread.php?t=1125414
(There it is shown properly)

First of all,
Download the update.zip from above links according to your model.
Then don't unzip and directly send to your device.
Then boot into recovery mode. For this:
Press the volume button up(+) and home button and the power button simultaneously.
Keep it pressed till it switches on.
Then select apply update from sd card.
(~Note~ Volume up and down will highlight and home button will select the option.
Touch screen is disabled.)
Then choose the downloaded file:update.zip.
It will take two to five minutes.
Then after the process select reboot system now.
It will take a little long for the first time to reboot but then it will take normal time.
After that you can see your menu
If there is an application called 'SuperUser' then it has been rooted successfully.