Front panel connectors

Solution
Depends on the actual pins and your motherboard's front panel header layout.

For 1-pin's such as PWR LED+ and PWR LED-, it doesn't matter if upside down or front side up as it is only connected to a single pin.

For 2-pin switches such as RESET and POWER, it doesn't matter too (whether + or -) as they are only switches, as long as they are connected to the correct two pins of your header.

For 2-pin LEDs, however, you need to determine which pin is + and which pin is -.

For other front panel connectors (such as USB3.0, USB2.0, and HD Audio), it will only go in one direction (due to the pin layout), so, check the socket orientation against the headers so as not to damage any pins.
Depends on the actual pins and your motherboard's front panel header layout.

For 1-pin's such as PWR LED+ and PWR LED-, it doesn't matter if upside down or front side up as it is only connected to a single pin.

For 2-pin switches such as RESET and POWER, it doesn't matter too (whether + or -) as they are only switches, as long as they are connected to the correct two pins of your header.

For 2-pin LEDs, however, you need to determine which pin is + and which pin is -.

For other front panel connectors (such as USB3.0, USB2.0, and HD Audio), it will only go in one direction (due to the pin layout), so, check the socket orientation against the headers so as not to damage any pins.
 
Solution
Your motherboard manual will tell you how the front panel header is laid out.
Be careful finding the proper orientation.
Make note of where there is a blank pin.
The PWR and reset leads are not polarity sensitive, so it does not matter if you have them wrong.
The led leads(PWR and HDD) are polarity sensitive and plus must connect to plus.
Usually the positive lead is the colored one; ground will be a common color like black or white.
There should be a small + or - moulded into the lead.
If you get the led + and - reversed, no damage will occur. The led will simply not light up.
Reverse them and you will be ok.

If you want to see some really strange behavior, connect the led leads to the reset button.
Again, though, not to worry, no damage happens.