I started plants in my house for my garden.Were doing great, now dead!

Were they getting enough light and water?

If they are yellow they are overwatered. If they simply bowed their heads, they probably needed more sunlight. If it's not too cold in your area, and they are not completely dead, set them outside and see if they perked up. With a little water and sun they may surprise you and come back to life. If not, that's the rule of thumb for next time. it's been my experience that overwatering is worse than under watering. Pick a day of the week that you water and make sure it's not too much. Just enough to wet the roots .

OH are you not suppose to water them everyday?

Not unless they are dry under the surface. Also they really do need direct sun light. That was my problem. The only thing that I got to grow from seed in the house was green peppers and they were a bit tall and spindly. I will have to see if they thrive in the garden.