4 Steps of a Total Eclipse
1. First Contact
At the time known as C1 (first contact), the Moon's disk will first touch the edge of the Sun. Now, the Sun is a very bright thing, and you cannot look at it without the right eye protection in front of your eyes. So don't try. Assuming you have the right filters in front of your eyes, and always keeping them there when you're looking at the uneclipsed or partially-eclipsed Sun, you should try and find that very first little nibble the Moon makes as it's first touching the Sun's disk. At this earliest stage of the eclipse, it's easy to see the "bite" in the Sun grow slowly larger. Over the next hour and a half, this bite will grow, and will turn the Sun into more and more of a crescent shape. You have to really use your imagination to visualize the moon moving in front of the Sun, because it looks for all the world like simply a big bite that's getting bigger as some unseen monster's hunger remains unsatisfied even after incessant munching. And there is absolutely nothing at all to see if you don't have the proper filters such as glasses to look through.
2. The Partial Phase Deepens. (EVERYTHING THAT FOLLOWS ASSUMES YOU ARE IN THE PATH OF TOTALITY!)
You don't have to be right on the centerline, but the closer to the centerline you are, the more totality you'll get. you'll still see all the effects of deepening partiality. You'll get the shrinking sliver of Sun. As the sliver thins, though, you get the very weird atmosphere that surrounds an eclipse, which is very difficult to describe. As the sliver of sun gets thinner and thinner, the sky darkens a bit, and the light around you takes on a weird, "clearer" quality. Everything seems sharper and clearer, though darker. It's kind of like if you were squinting, and everything seemed much more distinct to you. It's very strange, and it's a very powerful effect on your senses. As partiality deepens, and the sliver of Sun shrinks even more, the sky gets darker - very slowly, but noticeably darker. The wind picks up a bit, and the temperature drops noticeably. Birds roost, evening insects come out, and the world prepares for sunset in the middle of the day....
3. Onset of Totality
Partiality deepens even more, and the atmosphere actually starts to be a little scary. The sky gets deeper and deeper dark blue, a kind of gray veil falls over everything, and the Sun-sliver gets thin enough that you can actually (through your filters, remember?) start to see it shrinking as you watch it. The sky surrounding the Sun will grow very dark very quickly. In real time, you will be able to see the deep blue turn to twilight blue, and then to bluish-black. Stars and planets will pop out of nowhere. Roosters will crow and insects will chirp as though night is falling. The temperature has dropped maybe 10 degrees, and there is a positively electric energy that everyone around you is sharing. If you look to the west, you'll see a beautiful black curtain rising up out of the Earth, with hints of sunset-orange north and south of it, while off to the east, the sky at the horizon is still rather light. On the ground, your shadow will become impossibly clear and thin, and then will vanish completely as the Sun's light fades to about the intensity of the full Moon. In the last few seconds before totality, that dull blackness you saw off to the west will suddenly spring up out of the Earth, and take over the whole sky. As the last sliver of Sun melts away, you will be able to see several things happening simultaneously. You will now definitely have the feeling that there are two bodies involved, because it is impossible to miss the movement of the Moon’s disk in these last seconds. (You should still be watching through the eclipse glasses, by the way.) But while the last bit of the sliver is shrinking, the Sun's corona will start to come out. The last little bit of the Sun's light will glare through valleys on the Moon, and will create a "bead" effect at the edge of the Moon's disk. These are called "Baily's Beads", and they are stunning. These will dance around a little, and then will fade away as the very last one of them brightens into a huge bead. Around the edge of the Moon, the Sun's corona will begin to glow, giving us the famous "diamond ring" effect. It lasts for only about 2-3 seconds, but it is stunning beyond words. You will see the corona burst into view as the diamond fades away, appearing as though someone is smearing wispy-white cotton candy all around the impossibly black hole that's been cut out of the fabric of a blue-black sky. There may be tongues of red fire visible around the edge of the Sun - these are solar prominences, and no one knows what they will look like until they see them right along with you. The corona’s shape is like that, too. There may be predictions of what it will look like, but every eclipse is different.
Once you can't see anything at all with your filters (sunglasses), take them off! You will see nothing if you keep them on, and now, during totality, they're not necessary! Keep them in your hand for when totality is over, but use your eyes. Use your binoculars with impunity. Don't look away if you can help it. The diamond is gone, all the sun's light is blocked, and you're looking at the most beautiful thing you're likely to ever see - the solar corona, shimmering around the Moon's disk brilliantly (and which is only about as bright as the full Moon). It will look to you as though someone has painted the sky a deep bluish-purplish-black.
You'll know when totality is finally coming to an end, because the western sky will brighten dramatically.
4. After Totality
After the spectacle of totality, the views of the waxing crescent Sun will still there for the viewing.