Watering Seedlings?

Good Morning everone,
I am a complete newbie to seed starting and I am wondering how to tell when you need to water your seedlings.
I am sure it depends on the environment they are in, so I will tell you what I have set up.
I have an extra room in my house that is really warm, I have tall shelves that are 4' wide with 4' shop lights suspended over each shelf.
(I know it's too early to be starting seeds, but I am just practicing)
I have several seeds in peat pots (jiffy strips) in a dome thingy that have germinated, and several that I started in baggies and have transplanted to 12 oz clear plastic cups and left uncovered. The lights are about 3 inches from the surface.
I know to bottom water them, but how often are you supposed to do that? Also when would start feeding the seedlings?

Any advice would be hugely apprecaited. :-)

Seedlings have everything that they need for awhile contained right in the cotyledons. No need for feeding until it's time to put them in the garden. It's better not to promote growth in seedlings, and most plant food has a high nitrogen content. Making for more leaves and less roots. If you feel you must feed, use a very dilute fish emulsion. (it stinks) but it will be best for small plants with tiny roots. Don't overdo it. Fish emulsion is high in N also.

You need to get some air moving. Warm humid rooms with little air circulation is a fungus heaven. Prop your domes up so that air can circulate underneath.Put a small circulating fan blowing gently on the seedlings. Strengthens the stems.

I only use domes till the plants germinate. Then they're history. Some folks feel better about leaving them on longer. Since you are using peat, it might be better just to prop them up. Peat is a bear to keep properly hydrated. Top dries out, and the bottom gets moldy.

Your plastic cups are ideal, that's what I use, although 12 oz may be a bit big. Water from the bottom, let the water stand for 15 minutes to soak into the mix and then pour off excess. Seedlings are best when the mix is not saturated, a little in the dry side. They get waterlogged and disease sets in from too much 'love'. Look at the root of a just sprouted seed. It's just a little hair-like tail. There's no way it can take up much moisture.

It's like feeding a baby, there's a reason it can't eat much at one time, their stomachs won't hold it.