This product has been discontinued and is no longer available for sale.

The standard procedure for wiring an LED consists of the following:

Connecting wires to the 3mm and 5mm LEDs

Each LED has a round base with a flat spot on one side. The shorter of the two legs is on the side with the flat spot. This is the NEGATIVE lead. The longer lead is the POSITIVE lead.
Now that you know how to identify which lead is positive and negative, clip the leads so that they are about 0.3" (7.6mm) long. There is nothing critical about this measurement. It simply gives you room to work.
Using a pair of locking forceps, grip the wires at the base of the LED. Alternatively, use a pair of pliers. Hold the pliers in place with a rubber band around the handle to keep the jaws closed. The forceps / pliers will act as a heat sink while you do the soldering.
Holding the LED in position, tin each lead of the LED with a small amount of solder. Use a low wattage (low heat) soldering iron for all of this work. Otherwise, you risk damaging the LED.
Strip the ends of your wire. Twist the ends together and tin them with a small amount of solder.
Trim the leads so they are about 1/8" (3mm) long.
Place a piece of heat shrink tubing onto the end of each wire. It helps to separate enough length of wire so that the heat of the soldering step will not melt the heat shrink before you slide it into position.
Carefully hold one end of the wire so that it touches one of the LED leads. Touch the soldering iron to this connection with no additional solder and the solder will flow to make a nice connection. Repeat with the other wire.
Slide the heat shrink over the exposed metal leads. Use your heat gun to shrink the tubing tight. This will insulate the connection.

Connecting wires to the 1-Watt LEDs

These LEDs have two long tabs and two short tabs on them. On each side, you'll notice a long and short tab. One of these short tabs has a hole in it. The long tab on the side with the short tab with a hole in it is the POSITIVE lead. The long tab on the opposite side (the one with the short tab with NO hole in it) is the NEGATIVE lead.
Holding the LED in position, tin each lead of the LED with a small amount of solder. Use a low wattage (low heat) soldering iron for all of this work. Otherwise, you risk damaging the LED.
Strip the ends of your wire. Twist the ends together and tin them with a small amount of solder.
Trim the leads so they are about 1/8" (3mm) long.
Place a piece of heat shrink tubing onto the end of each wire. It helps to separate enough length of wire so that the heat of the soldering step will not melt the heat shrink before you slide it into position.
Carefully hold one end of the wire so that it touches one of the LED leads. Touch the soldering iron to this connection with no additional solder and the solder will flow to make a nice connection. Repeat with the other wire.
Slide the heat shrink over the exposed metal leads. Use your heat gun to shrink the tubing tight. This will insulate the connection.

Connecting the current limiting resistor

Trim each lead on the resistor to a length of 0.3" (7.6mm) or longer. Using a small flat blade screw driver, press one trimmed end into the rectangular channel on the mating connector. Solder this into place.
Insert the wire connected to the negative lead from the LED into the other rectangular channel on the mating connector. Solder into place.
Tin the second lead of the resistor. Put a piece of heat shrink tubing on the positive wire. Solder it to this end of the resistor.
Notice that a small metal finger protrudes from the metal pin that prevents you from sliding the pin into the housing. Using a small pair of pliers, bend this pin downward so that it clears the plastic housing.
Crimp the small metal fingers at the rear of the pin so that they hold the wire and resistor into place.
Push each pin into the plastic housing until you hear a small "click".
Slide the heat shrink tubing over the resistor. Use your heat gun to shrink this tubing.

The LED harness is now complete. If you followed the recommendations here, then you will plug the connector into the light controller with the resistor on top. Remember that the top pins are negative and the bottom pins are positive. Please be careful when soldering wires to the LED. They are sensitive to heat. They can be destroyed if you do not heat sink the LED, or if you spend too much time (more than a few seconds) soldering each connection.

This photo shows what the 1-Watt LED looks like. The clear dome is 5mm wide. The base is 8mm wide (not including the metal tabs). The total height is 6mm. The metal tabs are usually folded back once you solder wires to them. Examine the photo of the fresnel lens below. When you use the fresnel lens in conjunction with the 1-watt LED, you need to separate the mounting flange from the lens and discard it. Then you can cover the dome of the LED with the top portion of the lens and glue it in place.

This photo shows what a typical fresnel lens looks like: