We are wanting to grow tomato plants from seed this year. We've not done this before, so we have some questions.

How big should the containers be that we start the seeds in?

How long should they be in the containers before they get transferred outside? (i.e. how much before my outside planting should I start them?)

And, what am I forgetting/not thinking about? (I am asking about hardening in a separate question, but I'm sure there are other considerations that I haven't even thought of asking about)