Model rocketry is the hobby of building and flying model rockets. They can go anywhere from several hundred to several thousand feet in altitude at speeds upwards of 300 mph! Most hobby stores have these models for sale. Estes and Quest are the 2 main suppliers of model rocket related kits and items. Most hobby stores carry them.
It should be noted that you DO NOT EVER make your own fuel! This is dangerous and against the law. The solid propellant 'engines' that power these model rockets are professionally pre-made and pre-tested by certified manufacturers. You can buy these engines in various sizes separately from the model rocket kits (much like you buy batteries separately for your walkman).
As you gain experience with the hobby, you can even create your own model rocket designs rather than building the pre-made kits. There are computer programs to help you design, predict the flight characteristics of your models.
The model rockets are made out of cardboard tubes, balsa wood or plastic fins & nose cone. The nose cone (attached to the model rocket by an elastic cord) is able to slide out of the end of the rocket to allow the recovery device (streamer or parachute, usually made of thin plastic, light string, and tape strips) to deploy at the end of the model rocket flight.
Here are plans for a simple typical model rocket from Estes, called the Aerobee.
http://plans.rocketshoppe.com/estes/estK-17/estK-17.htm
(Just click on the image to enlarge it).
Here are more plans!
http://plans.rocketshoppe.com/estes.htm
Basically here's how your model rocket flight will work once your model is constructed and painted.
You insert the model rocket engine into the tail end of your rocket and insert a nichrome "ignition" wire into the engine nozzle (this allows the engine to be fired electrically from a remote safe distance).
In the front end of the rocket you insert flame retardant 'recovery wadding' (also available at hobby stores) followed by your carefully folded streamer or parachute. The wadding here is to protect your parachute or streamer from melting from the hot rocket engine gasses produced when the engine burns.
Finally, you place the nose cone into the top of your rocket and you are about ready.
To LAUNCH your model rocket you'll need an open field and a launcher kit which consists of a stable 'stand' that won't tip over in the breeze. The stand has a so called metal 'blast plate' which prevents your model rocket engine exhaust from hitting the ground directly.
The other crucial part of the 'launch pad' system is the so called "guide wire". This is a 36" (46" for larger model rockets) long stiff, vertical, stainless steel wire that guides the rocket as it takes off until it gains enough speed that the fins can keep it flying on course.
The launcher kit also includes a battery powered 'safety switch' that is used to run a small 6V or 12 V electrical current to the nichrome igniter in the model rocket engine to 'ignite' the solid propellent inside, from a safe distance (electrical means of ignition is used because it is the safest and most reliable).
And just like the real rockets at NASA, your launch 'switch' also contains a 'lock out key' for added safety so the switch cannot be accidentally "armed" and the model cannot be "ignited" or "launched" before ready.
So you take your 'prepped' model rocket (with engine and engine igniter wire inserted and your wadding and recovery device packed) and lower it down along the guide wire onto your launch pad. Then (with your 'safety lock out key' REMOVED from the launch switch and in your hand!) you carefully hook up the electrical battery source to your rocket engine ignition wire.
Then stepping back to a safe distance you can insert your safety key (there is normally a light that comes on at this point to let you know all is connected properly and working), give a 5 second countdown, depress your launch button and WOOOSH!
The engine has 3 burn phases. The 1st phase is the BOOST phase where propellant burns rapidly accelerating the rocket. In the 2nd phase, the engine burns a timed zero thrust smoke producing 'delay charge' that gives the rocket time to slow down as it coasts higher. The smoke trail also allows you to more easily 'track' your rocket as it coasts to higher altitude. 3rd, the engine ignites an 'ejection charge' forward to blow off your model rocket's nose cone and allow your recovery device to deploy so the rocket can come back to the earth gently and be launched again.
You can Google "model rocketry" for a TON of sites and clubs that will have all the info you need.
Also your local hobby store can be of great help in getting you started in this fascinating and fun hobby.
AND, be sure to visit your local library or bookstore and get your hands on the book called Handbook of Model Rocketry, by G. Harry Stine ...this is the bible of model rocketry.
Have fun!