Whole guide on how I grow my tomatoes (did I just wrote all that):

Germination: In seed trays and let them go for 2 weeks until they have a few first true leaves.

Seedling stage: I move them into red plastic cups with holes for drainage. This is when I give very light fertilizer as they are very sensitive when small. They stay in the cups for 3 weeks until they get at least 8in talls before transplanting into containers.

My experience tells me during this stage it is better to keep them under some roof or inside so they don't get wet from the rain, as it's possible to catch some airborne fungus (like septoria leaf spot) that will wipe out all your seedlings. I personally harden them off for at least two weeks before transplanting, by giving them partial sun, patio roof or shade cloths works.

Transplanting: I think high 70 to high 80*F is an ideal range for tomatoes. From my experience living in in Florida, it's the humidity that is the problem, not so much the heat. I believe this is why tomato grows very well in California climate. There are variety that are more heat resistant and some does better in cooler climate.

For transplanting into soil, let the plant get to at least 1ft tall first by transplanting them into 1 gallon containers first. For my situation there are more chances of pill bugs chewing the stem of weak seedlings in the soil.

Container mix: It's good to use a type of potting mix with good porosity, which mean it should hold water well, but at the same time have good drainage and aeration. Unfortunately, this require a bit of experience. I find MiracleGro potting mix are too water retention so I can't recommend them. "Pro-Mix" is a professional brand, but very expensive. I like "Ecoscraps" potting mix that you can get at Target, it have more 'fine pine bark' and perlite included than other brands, this gives it good drainage. However, I find their bags sometimes have 'fungus gnats' so definitely not recommended for indoor growing (some people avoid anything with fungus gnats, or microwave the potting mix).

If you feel your mix is too water retentive, you can add these amendments to help them drain: perlite, vermiculite, or fine pine barks. Mixes that have too much water that don't drain will become aerobic, when you empty the container you will smell ammonia in the bottom.

Personally I add some compost to my potting mix, but some people are completely against using compost in containers, so it's up to you (in this forum, "violently oppose" is probably more precise).

Avoid 'potting soil' which sometimes is mistaken or used interchanged with 'potting mix'. A lot of growers think soil shouldn't be used in containers because they are very heavy and compacted, and potting soil is exactly that.

Fertilizer: This is a loaded topic and more knowledgeable people can get very scientific into it, so I don't want to get too much into it. Tomatoes prefer fertilizer lower in nitrogen. Too much nitrogen will give you lots of leaves and reduces blossoming. I think it's fine to have a little more nitrogen during the early stage.

I prefer slow release organic fertilizers. For starter, you can use tomato specific fertilizers from the brands Espoma (Tomato-tone), Jobe's, or Ecoscraps, all should available at HomeDepot/Lowe's.

In my opinion and experience, it is possible to grow tomatoes completely without fertilizers if you have rich compost. Occasionally I do use synthetic fertilizer (low in nitrogen) sparingly if I feel a plant is deficient.

Management: I'm more OCD than others so I break off leaves branches in the bottom that are touching the soil (if you think you have healthy disease free soil then maybe you don't have to do it). Mulching the base of the plant is a good idea, but be careful because bugs can chew the stem and breaking or weaken it, so I always give the stem some free space.

I also break off bottom yellowing leaves and any that shows signs of bacteria or fungus infection. To me it's simply a good idea to clean off the bottom of the plant when it's larger to improve aeration which reduce pests and chances of disease.

I can't help you with curing diseases since I stay organic as much as possible. Some people use copper and/or Daconil to deal with fungus, even as a prevention spray. For pests control, I use organic peppermint soap + cold pressed neem oil diluted in water. (The reduced non-cold pressed neem at HomeDepot is useless to me).

Beware the dreaded whiteflies if you live in the South. Around here they often carry a disease called 'tomato yellow leaf curl virus', which to me is death for tomato plants, your option is to yank and trash because the plant can no longer produce anything worthwhile.

I find that both underwatering and overwatering can lead to "bottom end rot", which is the fruit rotting from the bottom.