How far should i overclock this system?

[xtrattitude4u]

Yay, I just got my computer! I am a noob to overclocking but am a quick learner and have been researching the basics lately. First, let's start with my specs:
Case: Thermaltake Armor Jr. (3 fans, 2 120mm, 1 90mm, stock cpu hs/fan)
Mobo: EVGA 780i SLI, 3PCIex, 6x sata2, 1333 fsb
CPU: Intel Core 2 Quad q9550 @ 2.83ghz
VIdeo: Nvidia 9800GTX (1) currently, will soon have (2)
PSU: 650w Antec Truepower Trio
(1) 20x SATA DVDRW, will soon have (4)
(1) 320GB HD, will soon have (2)

I have been using computers for a long time, but know little about OCing, and need some advice. I plan on adding 1 more 9800gtx so im not worried about the bottleneck there. What is a reasonable goal for a stable OC on the cpu with this system? What Cooling upgrades should i add if any? Any advice on the procedure for doing the OC or the timing values would be tremendously helpful.
P.S. If there's a way to cool this thing overclocked without liquid, i'm all for it. I hate the thought of fluids running around in my Brand new $1400 PC.

[Nagasama]

reasonable goal:
3.2-3.8ghz, depending on how much you want to mess with it.
cooling:
xigmatek s1283.
as far as ocing on the 780i, good luck. the last one i tried with wouldn't oc worth a crap, and when i finally got it to do some sort of respectable oc (which wasn't respectable to me, but may have been to some folks ha ha), the vdroop was staggering.
what kinda ram you got? hopefully not OCZ platinum...