Above & Beyond Expertise
Windows 7- Ultimate
Like Plastic Nev said in 99% of the cases the motherboard has markings ( letters ) next/above/underneath the pins letting you know which pair is what.
The Power Button Connector usually noted as PWR or PW or PSW has no polarity, you don't have to worry about it, just connect the corresponding cable to the pins marked with PWR.
The same applies for the reset button as well, it has no polarity, and you'll find it noted as RST or RS. Just connect the corresponding cable from the case to the RST/RS pins on the motherboard's header.
The other cables aren't really needed, but if you want them, they're usually mentioned as:
Hard Disk Drive LED = HDD LED or HDD or HDL ( you need to connect it properly, it is a polarized connector, depending on the LED on your case it might not light up or light up in a different color if connected improperly, no harm will be done anyway )
Power LED = PLED or PWR_LED, like above, it needs to be connected properly, as it is a polarized connector as well.
Speaker ( Buzzer ) = SPKR or SPR or BUZ
If you still have issues or questions, just post a photo of your motherboard's headers and another photo of the cables from your case showing the markings on them clearly