Rooting into recovery mode in Samsung Galaxy S is fairly easy, for simple basic way of how to root get into Recovery mode on the Samsung Galaxy S I9000 is by :
1. Turn off your phone.
2. Now hold the Volume Down Home Power buttons, until Samsung logo, stop holding it for second & then again hold it.
3. Your phone will now boot into the Recovery mode.Other Ways of getting into to Recovery Mode
Following video shows ways, how to access to Recovery mode by using:
[youtube]Samsung Galaxy S Clockwork Mod Recovery Mode & How to Fix Android SDK Error Tutorial
1)Accessing Recovery mode without using computer
2)Installing Android SDK on your computer and use command prompt
3)Installing Rom Manager to phone & use Clockwork Mod recovery image