CHI SAO
The above video goes in depth on the training methods of the shaolin monks and gives insight on their methods and philosophy for developing chi energy and directing it for desired strength in different techniques. Some will probably even amaze you!
This video is a good example of Chi Sao exercise. I like it because the latter half is in slow motion so you can really observe the techniques and form as the two Wing Chun practitioners react to each others movements.
The man on the left in the blue is Ip Chun. He is practicing Chi Sao, or "Sticky Hands" with Master Rawcliffe. By staying in contact and feeling for your opponents movements, with practice you can sense and counter or deflect attack effectively.