There are probably cables coming from the front of the computer. On the motherboard, you will see 2 or more groups of pins where these cables go. Unfortunately, sometimes the cables don't have a single plug, but have one plug that has 3 holes and then 1 that has one. Many times, too, there are 2 sets. So--let's see if this helps:
The pins will be labled something like USB and then several numbers.
The pins look like this ::::. (hope that shows up OK)
If your usb cable end has one large (3-hole) plug and one small, the large one goes over the first 3 pins from left to right. The one on the left is labeled VCC. The separate plug goes on the 4th pin.
You can use the top row of pins or the bottom. Nothing goes on pin #5 on the bottom.
Does this help? If so, rate it accordingly, please.

Find manual for your exact motherboard and read there.