When you are learning how to punch and to put power into your punches it is very important to get the basics right. There are a number of different types of punch that you can use with different techniques for eache one, and even for the same type of punch you might find different techniques being used in the many different styles of martial arts that there are. On this page I will provide what I think are the best resources for you to use so that you can learn the specific techniques for good powerful punches, including some of the best videos from YouTube, Books and DVDs from Amazon and links to other websites and online articles. But before you get to the specific techniques it is worth taking a look at these basic principles which I have put together to help you get it right:

1. Keep your body as relaxed as possible until the moment of impact: When you are in a fight it is obviously a very stressful situation and the natural tendency can be for all of the muscles in your body to tense up. Also some people associate tensed muscles with strength and power, and so might tighten and tense up their muscles before or during a punch thinking that this will make it stronger, but actually the opposite is true. Firstly, if you are tensing your arms and shoulders then you won't just be tensing the muscles required to for the punch, you will also be tensing the muscles which perform the opposite movement. This means that you are tensing muscles which actually oppose what you are trying to do - so you end up fighting your own body as well as your opponent. Secondly there are different kinds of muscle fibers for different functions, commonly known as fast twitch and slow twitch. The explosive kind of power needed for a strong punch uses fast twitch muscle fibers, but a tense body will be bringing slow twitch muscle fibers into play in a situation they aren't made for, which again reduces your power. Basically it is just simple interference - if you keep your body as relaxed as possible before striking, and then just concentrate on speed and technique during the strike, there will be no interference and your body will be working at maximum efficiency. As you land the strike you should then tense up, not only your fist, arm and shoulder, but also your chest muscles and abdominals so that your body is rigid and unyielding.
2. Speed is all important: The power generated in a punch depends equally on two things - strength and speed. A small person who is not particularly strong can generate a large amount of power if they can genereate high speed in their movement.
3. Generate torque: You can add a great deal of extra power from your hips and the core muscles of your torso through a twisting movement of your upper body. This is particularly true with a cross punch. This twisting movement should begin at your hips as you push off your foot and push forwards your hips on the same side as the arm you are punching with. Also use your torso to turn your body so that you are pushing your shoulder forwards on the side that you are punching from.
4. Step into the punch: This is a pretty obvious one really. Stepping forwards into a strike will help by putting the weight of your body and the strength of your legs into it as well as the strength coming from your upper body.
5. You have to train to gain: Like everything else the single most important factor in how good and how powerful you are going to be is how much you have training and practiced. If you can get access to a punching bag, especially a heavy bag at a local gym or at your home then this is obviously the best training that you can get. A bit of strength training also helps, focusing on your triceps, deltoids (shoulder muscles), pecs (chest muscles) and abdominals is the best thing. So that means push ups and dips (and / or bench press and overhead press), and lots of crunches, sit ups and the like. For uppercuts and hooks you would also be using your biceps.
6. Follow Through: This is very, very important indeed. When you strike, whether it is a punch, a kick, an elbow strike or whatever, you should always follow through after contact. Although it is not always possible, and perhaps not appropriate for every single punching technique that there is out there, as a general rule you should always aim for a point which is a minimum of 6 inches behind where you will actually strike. The worst possible thing that you can ever do is to 'snap' your arm so that you stop as soon as you make contact. Doing this is basically the same as what is known as 'pulling your punches'. Having a large follow through not only adds power to your strike at the point of contact, it also increases your chances of knocking your opponent off balance.
7. A Strong Stance: In Kung Fu they say that the stance is the most important part of fighting, and there is a lot of truth in that. It is often neglected, but a strong stance is necessary for strong techniques. Your knees should be slightly bent and your feet should be 'squared', meaning that there should be the same distance fowards and backwards as there is left o right between your feet. As you land a punch your back foot should push down and back into the ground as hard as possible.