I'm not entirely sure what happens with other people, but with me the process was:
1) First there is a tingling along the hands and the top of the head.
2) Then the crown (top of the head) gets really sensitive to touch.
3) And then the energy pours in from every living source. The process clears out any illness or impurities, which is why alcohol and drugs is avoided by monks and priests that try to achieve this state.
The energy also covers the eyes, meaning that when the eyes tear up, the salt will conduct the energy and sting really harshly, like being shocked in the eye, except by your own tears.
4) After the initial period of being filled with the energy, a second state begins where the body draws in energy on the top of the head from the sun, the Earth, and other sources, and energy can also be drawn into the body from the hands and feet.
The eyes can also emit the energy and shift modes to see the energy network within people and in nature.
Thing that I've learned to do thus far:
1) Energy needles: this is emitting energy from the fingertips that are sharp like needles. This is used in medicine to do acupuncture without needing real needles. It can also be used as a weapon to damage people, but then again, so can normal hands.
With me it's on automatic, though I don't know if this is the case with everyone that can do.
2) Palm emission: the energy gathers very intensely from the palms, more so from my right hand.
3) Distant detection: I can detect energy signals in living things from a distance.
4) Atmospheric detection (this one is the most fantastic sounding):
I can feel changes in the atmospheric qi energy. One encounter was when a flock of birds flew over me, I could feel the signature of every bird across my head. And when there were fireworks on the 4th last summer, I could feel every explosion go off in the atmosphere, even though I was in my room, inside of the dorm building.
5) Vampire style absorption: when I'm low on qi energy, I feel a certain pull in my system that I can only describe as a vampire's desire to drink energy. When I'm low, I just absorb energy from nature. Although parties are good for "feeding" as well, since people dancing in a group build up enough energy to not know they're being drained.
Things that I can learn to do, that I'm studying now:
The Iron Skin technique: exactly what it sounds like, where the skin becomes as hard as iron. It's used in the martial arts.
The Iron Bone technique: the bones become as hard as iron rods. Again, I think this is a defense mechanism that people have just forgotten about.