There are probably as many ways to start seeds indoors as there are gardeners. Mandolin suggested we share what we do, in case it might help someone else.
It is pretty basic really. We have metal shelves that just fit over our kitchen propane fireplace. This provides a heat source at no additional cost to us.
We use the smallest plastic solo cups for the seeds. We cut drainage holes in them by turning a whole stack upside down, and using a sharp knife to make slits. Keeping them stacked prevents the cups from collapsing under the weight of the knife.
After putting some seed starting mix into the cup we place the seed on the mix, then add enough mix to make the seed planted at the depth suggested on the seed packet. Water a little, and place in a plastic tray. The trays we use are from a company called Planter’s Pride, and they originally came with seed starting pellets. We prefer the cups though, and the tray holds them in place. The lid has a cutaway on each side to allow for air flow. You can also just prop the lid a bit if you have a different brand.
We cover the plastic tray, then put that on an enamelware tray that sits directly on the fireplace. This buffers the heat perfectly. A cookie sheet would do the same.
As the seedlings emerge and grow, they graduate to larger cups and move up the shelves. Later in the season when we need more room, an additional light is hung over the top shelf. If we want to have more than one tray of starts, we just alternate their places on the shelves or fireplace every few days. When they sprout, again, they move to a higher shelf.
We keep track of what is what by numbering the cups with permanent marker, and keeping a list on the computer.
More tips on starting seeds indoors.