You'll find it pictured in the Service Manual...
Go to this page:
ENGINE MECHANICAL (H25 ENGINE) 6A2-11
You'll see a diagram of where the IAC Valve is on the 2.5 V-6. That diagram is showing the BACK of the engine, so the IAC is on the very top / back of the engine, slightly to the drivers side (US Models) as looking from the front of the vehicle.
'99 Grand Vitara JLX, 2.5L V-6, 4WD, 5 spd std, '00 "Limited" leather interior.
'03 Honda Odyssey
'72 Chevy Nova. One owner, SB, A/C, power disc/drum & steering.