It's really not too difficult. I use one of those butane long neck lighters. You have to take off the outer cover, then some have an inner cover to reveal the pilot light area. There is a dial there that has the selections of "off", "pilot", and "on". First turn the knob to off. Leave it off for a couple of minutes to clear the safety valves (this shuts the gas off when the pilot light goes out). Then I usually light the lighter and turn the knob to pilot, sometimes you have to also push in and hold the knob in, but you should be able to hear the gas and light the pilot light. You may have to hold the knob in for a few seconds if the gas has been off for awhile, but pilot should remain lit when you let go of the knob. Now my water heater has the knob on the outside of the tank, so I put the covers back on before I move the knob to "on". If you don't put the covers on before you turn it to on you will hear a kawoosh, because the thermostat setting will have the gas burner light up to heat the water. Just don't be alarmed, you can still put the covers on, it's just a bit warmer when you do it. Oh, and the very first thing you should do is to be sure you don't have an ELECTRIC water heater..........