I have to drain the water out of the tank so no water does come out when I take off the relief valve, don't I? Also, what do you mean when you say turn off cold water supply to heater and lift safety to take pressure off tank. Lift what??

Real simple

If you want to darin the tank a bit be my guest BUT there is apossibility the drain valve will not close all the way after you are done draining. That is why I posted the explanation of the cap etc.

If you do not turn off the cold water to the water heater it will still be under water pressure and no mater how much you drain it will keep filling back up.

The valve that is leaking usually has a tab/handle/device to allow the valve to open manually. By doing so you release the pressure of the water or allow air into the tank to allow service work to be performed.

Do a Google search on water heaters/water heater repair. There are 1000's of sites that can guide you through the replacement of the valve with pictures.

Now before you get into trouble if you feel that is possible call for ON Site Service and have someone else do the valve replacement.

Any good sites that you see?

There are a bunch of sites. Do the Google thing.