Here's a post about seed starting.
Once upon a time, long long ago, my seed starting methods were kind of haphazard. I'd go around the yard and collect a bunch of nursery pots, the 4" kind, fill them with garden dirt, then empty my seed packets into each one. The more the merrier, was my adage.
I'd watch as the seedlings germinated - a tangled, leggy mess. Some would die from damp, most just lay there, struggling. Eventually I'd toss the lot in the compost and buy ready-grown starts 3 months later. It was mildly stressful, now that I stop to think about it.
As the years wore on I had more success, but I didn't much enjoy seed starting season. It always seemed such a high-maintenance process. So fraught with disaster. Then I happened upon the BBC Gardener's World magazine. All the gardeners used tidy, sectioned, black trays, special seed starting soil, and special heat mats. Their seedlings were strong and mesmerizingly green. Accordingly, because I am nothing if not highly impressionable, I bought some black trays, some seed starting mix, and a heat mat. All of a sudden I had organized trays of healthy seedlings. No damp anywhere. There was still the minor issue of emptying the entire packet in each module, but that was solved with some early but judicious thinning.
The spring I had 129 tomato seedlings jockeying for room in a small, plastic greenhouse AND on every available south-facing windowsill in the house, I had to admit that my More! More! More! seeding habit needed curbing. I live in a city lot - it's roomy but it's no farm. So I tried the One Seed/One Square method
Sheila's Seed Starting Pictorial:
First, seed trays. Good for the city lot gardener. Cheap, durable if handled politely, and two can fit easily onto one large heat mat. Yes, you can use any old pot you have kicking around but these compact modules don't require a lot of soil, they won't tip over when you move the tray, AND they will hold one largish tomato/pepper until you transplant it out into the garden. Plus, they are easy to store.
Next, proper soil. I use a product called Sunshine Mix #4. Whatever you use should be well-draining or specially formulated for seed starting. Fill each module 3/4 full of soil and water well. Then add your SEED. Cover with a little soil. Water again, but only slightly.
Heat hats. I like these. Yes, they are an absolute pain to store the rest of the year but they add Instant Atmosphere to the process. They keep the soil moist, warm, and slightly humid. This is important if you are keeping your seeds in an otherwise unheated place, like this greenhouse. Yes, this IS the high-tech version of a plastic bag, but it holds its shape better than a plastic bag.
Heat Mats. I like these too. You can cut the germination time by at least 1/2, if not more, by using heat mats. They will also keep any tomato or pepper perfectly happy through the worst spring imaginable, until it's time to go out into the garden. Shop around: our local agricultural store charges 30% less than the local garden centre.
Label. Label all your seedlings, even if you think your memory is stupendously amazing. My method is this: (plant name) Black Krim, (date) March 1st.
I always place the tags in the same place on each tray: middle centre. This way the tag won't catch the heat hat if you're like me and you like to constantly see how your little seedlings are doing.
Thin. Once the seedlings are about this high I thin them out and move them around a bit, so they aren't always on a heat mat. Tomatoes and peppers get most heat mat time. Some seeds, like annual flowers or quick sprouters like lettuce, don't get ANY heat mat time.
Rotate For Light. When the seedlings are up and growing, rotate the trays each day or two, so the light is evenly distributed. Switch sides on the heat mats, turn them around, and so on, so the seedlings have the opportunity to grow straight.
Growing up out of the nursery. If you're like me and you've got way too many seedlings, turf some of them out to the cold frame.