I'm not sure you will have the best of luck with Ntune, my experience with it has been pretty bad. It simply makes my system reboot or lockup whenever I tried to use it for overclocking purposes. So you would be better off just doing it the old fashioned way by going into the Bios and changing your values there.
Secondly, you say you have the Zalman Reserator? Being that, that is a passively cooled h20 system your cooling performance with it wont be a whole lot better then if you were just using traditional fans. With that in mind, just keep an eye on things and watch your temps! Its good that you have case fans still, but you regardless of having h20 cooling you want to have those anyways.
Now, if you are looking to OC your CPU, I say start there and only there. Keep everything at its stock settings for now. Now, if I remember correctly the 3200 had a unlocked multiplier correct? If thats true, then this will be cake. Just increase the CPU multiplier to something a little higher then stock. I don't remember the clock speeds of that CPU, but I would start with a modest OC of around 100mhz, then test it and increase a little bit at a time until you find the sweet spot. Then if you want, you can start OC other parts, Perhaps your GPU would make a good next target.
Anyways, that should be enough to get you started in the right direction. Welcome to the world of OC! 🙂