I would eventually like to start growing vegetables and herbs from seed. I know with some vegetables when growing them from seed you should avoid transplanting them like the plague because they're just not suitable for it. Which vegetables transplant well and can be started in starter pots and which should be planted where they're to grow? These are the vegetables I would like to grow: broccoli zucchini tomatoes onions lettuce spinach baby carrots sugar snap peas eggplant (???) bell peppers (red and green; the sweet kind) These are the herbs I'd like to grow: chives oregano rosemary basil parsley cilantro marjoram Also when you start plants in starter pots what size pot do they need to be transplanted to when you transplant them (4", 8", 12", etc.) I realize this varies depending on what veggie and/or herb you're growing. Do you need to harden the seedlings off prior to transplantation?
From your list baby carrots, an sugar snap peas should be directly sown in the ground IMO an from my experience. I don't eat spinach, but I do grow the malabar climbing. An yes anything you grow from seed need to be hardened off first. A good rule to follow when bumping up plants is to go with the next size larger than what they are in.
Planting in the North is way different than the South. But here is what I would do- Start Early: Broccoli Tomato Eggplant Onion (Seed) Pepper Basil Direct Sow: Lettuce Carrots Peas Spinach Chives Parsley Cilantro