How do I update the OS on my device?
I have a Samsung Galaxy S (LCD version) with stock Android 2.2. How can i upgrade it to Android 2.3?
Install KIES from the Samsung website and connect your phone to the PC via the USB cable. If a system update is available, KIES will inform you and walk you through the upgrade process.
If you'd like to install an alternative ROM like CyanogenMod, you'll need to follow relevant installation details on the site or alternatively use an app like ROM Manager that can help do the needful.
As with all upgrades, back up your data to another location.