Can some one please tell me where i hook up my photosensor to an arduino diecimila board. it has 3 female headers and i gues i put it in icsp male headers but i dont know. is that right? trying to get some pics.
i think the header on the photoresistor wires is called a molex? anyway, i need to know how to connect it to the mic and the only male pins is the icsp thing.
your question is really vague.
What kind of photoresistor is it?
model number, where you bought it, anything.
also, just because something looks like it plugs in, doesnt mean it goes there. pretty sure the only thing that plugs into the icsp socket is a programmer to flash the chip without the bootloader. i wouldnt mess with it.
Do you have a picture of the device? Photoresistors have 2 terminals.
the product is called robonova from Hitech Robotics. 
Specs: Operating illuminance = >80Lux * Operating Voltage = 5v * Dimensions = 12.9mm x 14.6mm * Weight = 5.8g * Wire Length = 322mm.
I don't see any specs for this but one wire is 5v, one is ground and the other is your signal. Did it come with any documentation?
And what if my photoresistors only have two terminals? Would I be able to plug them in to the 5v power and analog input to read the level of light as a number? or is it a basic ON/OFF sort of thing?
CdS Photoresistors (LINK)
One to the ground, the other to the analogue input, then a resistor from the analogue input to the +5v. Try a 10K resistor to start but it changes the sensitivity / dynamic range.
Just jam both the wire and resistor in to the same analog port? Or I assume there some nice way to solder it all together and just have one wire in to the analog port?
Don't matter, either.