Jumpers and Headers on mobo (first time assembling)

[Esparko2]

Hello,

Sorry if it's in the wrong forum - I dunno if it goes in motherboard or computer help..?
Anyway.
It's my first time assembling a PC from scratch and I'm confused on the jumpers and headers on my motherboard.

The motherboard is an EMAXX P43
http://www.emaxxtech.com/products.php?id=17

Upon reading the manual to see where the jumpers and headers go I come upon this:
http://i.imgur.com/KhRYa.png
I'm assuming that's positive and negative? But on my cables I don't see anything stating what side is positive and what side is negative. My friend who has built his own PC before said that he didn't encounter anything stating positive and negative with his GIGABYTE motherboard.

But this is what I see on my jumpers/headers
http://i.imgur.com/BPIOd.jpg

Is that arrow suppose to signify positive/negative?
Or does it even matter which direction I plug it in in the end?

 

[MagnusTheBrewer]

The embossed triangle denotes pin one (negative).

 

[Esparko2]

Okay, thanks.

Lastly, the Power LED.
http://i.imgur.com/xppHd.jpg
http://i.imgur.com/8EACs.jpg

It takes up 3 pins. In the manual it says that it should only take up 2 pins. It can't fit because the power on button is taking up space. Is there any way to circumvent this? Or will I forever be without a power LED?

 

[MagnusTheBrewer]

The power connector does only use two pins but, it looks like the terminal in the picture has an empty slot between the two leads. If it is indeed the power connector (follow the actual wires to confirm), you may be able to move one of the leads to the empty center slot and just let the connector hang out over the far end away from the jack congestion. It's fairly common for cables to be mislabeled since assembly is usually done by non English speaking workers.

 

[Esparko2]

How does one go about doing that?

Do I just pull on the cable until it's free and then I just basically shove it into the middle slot?

 

[discerning]

There's usually a flap that keeps the pin in place. Use a precision screwdriver (or similar) to lift the flap a little, then pull on the wire while holding the flap up.