What happens after germination and after that?
This article will help you:
https://www.gardeningknowhow.com/special/children/basic-plant-life-cycle-and-the-life-cycle-of-a-flowering-plant.htm
Well once a seed germinates, which is the root or sprout coming out of the seed it will establish a root and grow a sprout...the sprout will make its way to the top of the soil and through it to grow your plant. If you are planting seeds depending on what variety you plant will depend on how long it takes to germinate..anywhere from a couple of days to up to 2 weeks for some things. Once your seedling is produces its second set of leaves you should be able to safely transplant it to a larger container. When you transplant it bury it in the soil up to its first set of leaves. If you need more info try to give us a little more information on what you are growing and we may be able to help you better,
This spring I have ordered a couple of different tree seeds. The seeds themselves are on a larger scale. One end is usually pointed, while the other is rounded. Does it make a difference which end goes up and which goes down?
In general, it usually doesn't matter which way the seed is planted, as in nature they typically land, germinate, and grow as is.
How many seeds from a packet should you plant in each hole?
As a general rule of thumb: three. This allows for the possibility of at least one not germinating or being eaten (by birds, etc.). Once they come up and reach about 6 inches hight, you can thin it down to the strongest plant (or two).
What word is used for seed germination in which the first leaves appear above ground?
Those are called cotyledon leaves.
When a seed pod on the stem from a living plant (not yet dried out, that is the plant!) is taken and dried out, are these seeds able to produce seedlings/plants? Or do I need to wait until the plant is completely dried out (dead) from these seeds to produce?
It really depends on the plant. What kind of plant are you trying to harvest seeds from?
It is best to allow the seed pod to dry on the plant. There is a trick with some plants to catch the seed if they drop from the plant before you pick them. There is great variance in how this is handled dictated by what kind of plant it is. You can research "Saving Seed" on the internet and specify the kind of seed you wish to save.
What is the warmest the soil can be for seeds?
Normally the soil temperature should be about 60 degrees F, before planting seeds. Luffas squash will germinate and grow at soil temps of up to 95 degrees. Most seed does better germinating at between 60 and 80 degrees. A lot of this depends on the type of seed you are planting.
Is it too late to put seeds in for sprouts this winter?
That would depend on what kind of sprouts you are planting and where you live. If you are talking about bean sprouts, you can plant those anytime and grow them in the house very easily. This article will help:
http://www.wvu.edu/~agexten/hortcult/homegard/sprouts.htm