In short, rooting is not for everyone depending on your needs/wants with the device. The process can be rather easy to follow, though, you do want to make sure you fully understand the pros and cons (if there are any cons :P) to rooting before jumping in.
Do you use the command line (like a terminal app or the shell in adb) and constantly find that you can't do what you want because there's no su command?
Are there apps you need to run, but can't because they require a rooted phone?
If the answer to both questions is no, you don't need root, because all rooting does is add the su command (and an app to access it). (Unfortunately, some programs that root the phone also make other changes, and leave garbage all over the phone, which can lead to almost undiagnosable problems further down the line, leading you to have to reflash a stock ROM.) It won't change a thing you currently do with the phone. It won't make it faster. It won't give you more storage. It won't give you better signals. It will just give you the su command. (And if you have no idea what that is, and don't need apps that need root [which means that they need the su command], there's no reason to root the phone.)
There's one reason to not root it - a rooted phone can't be updated. Not OTA and not with Kies or any other updating program. Part of the beginning of the update process is to check certain files (that may/will have been changed by rooting. If the phone is rooted, the update aborts. (With Samsung, it's usually at about 25%-30%.) Updating a rooted phone could brick it, depending on what you did when it was rooted, which is why the update won't do anything.