Your question is a bit unclear, but i have the same mobo, so lets see... I am assuming that when you hit the power button that nothing at all happens, no fans spin up, nothing.
Make sure your processor heatsink and fan are installed and connected. (i know, but hey, thats the first thing to look at !)
Having the LED leads reverses and not getting the light to come on is quite common and no big deal, but if the machine is not powering up when you press the power button, lets check a few things. First of all make sure your power supply is plugged in and that the power strip (if it is plugged into one) is turned on. Now check the back of the power supply to verify that it is set to 110/120 volt setting and if there is an on off switch on the supply itself that it is turned on. This has bitten me enough thet it is the first thing i do when connecting up a computer is check the supply switch.
Now, check the connections to the mobo, the power connector is fully seated on the board. You have at least one stick of RAM installed and it is fully seated and the processor heat sink fan is plugged into jack CFAN1 (on the top edge of the board between the RAM and the processor). If nothing is connected to this jack it is possible that the system monitor will not allow the processor to power up.
Make sure that the wires in your case are labeled correctly and that you have the wires from the power switch connected to the top right hand side of the JFP1 connector This connector has 5 pins on the bottom row and 0nly four on the top row. The power switch in on the top row next to the missing pin. This is on page 2-16 and 2-17 in the motherboard manual.
The power LED can connect one of two places depending on the connector you have in your case. If it is a two pin connector, it goes on JFP1 next to the power switch. If is a three pin connector with an unused pin in the middle, then it goes on the bottom row of JFP2. LED's are polarity sensitive. In the LED doesn't light up when the system is up and running, power it down and reverse the connector. The power switch leads can go on either way, they do not have polatity.
If the system STILL doesn't turn on, it is possible that your power switch might be bador damaged. This is very unlikely though, but try connecting the reset button to JFP1 and see if that works.