First up, what's the best source of information to learn about computer power supply connectors? It's definitely the motherboard manual. Most motherboard manuals have specific instructions on how to hook up the computer power supply connectors to the motherboard. Review the manual carefully to make sense of those connectors.
 

Some computer power supply connectors

What are the types of computer power supply connectors, you ask? Well, here they are:

• Power to hard disk drives There are connectors which power the hard disk drives - you hook these up directly to the power suppy unit using the power cables supplied.

 
• Power to the CPU The CPU is powered by a power supply connector hooked up to the motherboard. This is usually a small little connector you need to be familiar with your motherboard manual to ascertain what connector this is.

 
• Power to graphics card Most of the heavy duty graphics cards in PCs have a separate line to power them. The power supply connector to graphics cards might come from the power supply unit, or the motherboard.

 
• Power to computer beeper Notice how your computer 'beeps' when you first boot it up? That beep sound is powered by a computer power supply connector. You usually hook that connector between the motherboard and the power supply unit.

 
• Power to LEDs and lights Your computer case will have LEDs and lights to indicate activity in the computer (e.g. hard disk drive activity). To power these lights, there are some small power supply connectors between the power supply unit and the motherboard as shown below
   

  

  Power supply connectors for your computer case's lights

• Power to floppy and optical drives Your floppy or optical drives will need to be powered by computer power supply connectors. These are usually hooked up between the drive and the computer power supply unit.

Whenever you're dealing with the computer power supply, please ensure that you've grounded yourself properly. Very often, I hear of motherboards being short-circuited simply because the user forgot to ground himself or herself before meddling with the computer power supply connectors.