Pads and brake fluid (nothing fancy, ATE superblue is fine)
I don't think the OEM/OEM type pads will do so well on a track day. I'd recommend something better.
I'd also change oil before and after.
Really what you need to do is make sure everything is in great shape. CHECK YOUR ROTORS FOR CRACKS.
Expect the LCA bushings to tear after a few trackdays, but you can deal with it when you get there.
Me, i'd do in order:
Brake fluid-->pads-->oil change-->oil temp/pessure gauge-->tires-->a good alignment--> good suspension -->sways (people do sways first because they're cheap, not because they're a good first step. They are more for adjustment, not fixing the car.) -->front LSD -->cooling (may be needed earlier in some climates) --> maybe power
Please note that I don't view anything beyond the oil change as necessary.