That's why I'm glad my Shifu makes DVDs. After about six months of Taiji practice I asked my Shifu to teach me qigong for a while. He spent about three months teaching me all the basics--how to breath, how to meditate, how to do the exercises, etc. and then he kindly gave me free copies of his DVDs and book for me to practice with at home. After that I switched my focus to Praying Mantis and started spending the majority of my class time on that while continuing to practice qigong at home with the tapes. Otherwise I could never remember the proper way to do all the exercises! Even having owned the tapes for over a year now I still do the exercises with them because I'm always noticing new things or understanding things my Shifu says in them that I didn't understand before.
As far as the qi system is concerned, what would you like to know? The largest qi reservoir in the body is the xia-dantian ("lower elixer field"), located about three finger's width below the navel and in somewhat. Through the practice of qigong, we learn to sink the energy in the breath down from the lungs and into the dantian. From here it flow through the two primary vessels and can also be sent out to the limbs. The two primary vessels are the dumai ("governing vessel"), that runs from the dantian, down around the perineum, up the spine, over the top of the head and to the nose. This then connects to the renmai ("conception vessel"), which runs from around the the nose down the front of the body to the dantian.
Next in importance after the two vessels are the shi-er jing-mai (twelve meridians). There are twelve on each side of the body, so there are actually twenty-four. There are six of these flowing to the fingers and palm of each hand and six of these flowing to the toes and soles of each foot. Each of these is associated with different organ systems. Acupuncture works on the idea of using needles to adjust the energy flow in these meridian, thereby harmonizing the organ systems.
As far as martial arts are concerned, it is important to open these meridians up and learn to send energy from the dantian down each one. This allows you to have more powerful, explosive strikes, and also to perform more advanced moves like dian-xue and duan-mai/dim-mak ("pressure-point attack" and "sealing the artery"). I don't know how to do these more advanced moves myself yet, but I can send the qi flowing to different fingers at will. You will notice as you punch that if you concentrate on a different knuckle you will feel the energy flow in a different way, causing the torque and feeling of the punch to change. Supposedly advanced practitioners can also use this to cause what might look like the same punch to have different effects on the opponent.
If you want to know where the meridians are located and what organ systems they are associated with, I suggest you do a web search for acupuncture charts. If you have any more specific questions about how we train the meridians, how this applies to martial arts, etc. feel free to ask and I will answer to the best of my limited knowledge.
What senses do we lack that we cannot see or hear another world all around us?
--The Orange Catholic Bible