Your motherboard might not have any but new ones should. This is an example of what one should look like:
- A better example
This is all you have to worry about in that case if you know it was the right one. It will need just resetting
In terms of position, it depends but it could be near the battery, or a bit below the battery.
Usually if the jumper is set to position 1, you'd set it to position 3 to reset it, and then after a bit, place it back to 1. This is how ABIT boards work.
Taking out the battery is another option, but will take a while to work, whereas the jumper does it almost straight away by directing power somewhere else.
Post when you do it if it works