First of all, if you have the Nexus S (4G) then you HAVE the latest OS (gingerbread, currently at 2.3.4). Secondly, rooting is a personal decision. You don't NEED to root any Android device, especially a Nexus device. That being said, the Nexus line are considered "dev phones" meaning they are devices that are easily "rooted" to enable actions a "consumer" might not need, or care about (or understand). I personally buy only "dev phones" (G1, ADP2, Nexus One and Now the Nexus S) because I am interested in running custom ROMs, kernels, themes, ect... But, that's just me. Ask yourself why you would WANT to "root" the phone. If you decide that the answer is yes, I recommend androidcentral.com (geared more towards the consumer)or xdadevelopers.com (geared more towards developers and those interested in learning development) and finally cyanogenmod (google it). Otherwise stick with the iPhone.