Dome lights on but no power anywhere else, changed lock cylinder, car wont start please help

It sounds like a ground, probably at the negative side of the battery terminal. Take both cables off at the battery (a pain, I know) and clean the leaded contact area at the cable using a wire brush. Do you see any white or black stuff? That would be corrosion and even a tiny bit of it can cause your car not to start. Have you had problems since the head gasket has been changed? The ground from the battery to the block may have come loose. You could also try disconnecting the cable at the starter then to see if the starter is the culprit. Sometimes they short out internally. Check your fuses also. Start at the kick panel on the right side of the console. The other panel is located on the left side of the engine compartment, under the hood. I hope this helps.

If you charged the battery, it wouldn't matter if the car started or not, you should get dash lights. if i was a betting man i would say that you are not getting a good ground between motor and body of car. a poor ground messes up everything.