Air Radio Systems
  We suggest that you get a 4-channel radio with NiCds to start with. Even if you are only flying 2-channel airplanes and sailplanes, NiCd batteries are worth the extra money. Other useful features you’ll want to consider are servo reversing and a trainer system. Select from the other features to suit your future needs. You might not use them to start, but they will be there when you are ready. Be sure to match the radio system to the aircraft you intend to fly. Since there is such a large range of model types, you should select the type of radio to suit your particular tastes. If you’re going to be flying a .40-.60 sized trainer, a basic 4-channel radio with standard servos will be fine. You could easily buy more radio than what you’ll need, but save your money for things like fuel, glue and field equipment.

Great Starter Airplane 4-Channel Systems
  If you’re looking for a high-quality, 4-channel airplane radio, then look no further than Tower Hobbies’ own 4-TH 4-Channel FM. It has all of the features you’ll need and allows you to choose a combo with the number of servos you want to invest in.

Futaba 4YF 4-Channel FM Radio Systems

Futaba 4EXA Super 4-Channel FM Computer Radios

Hitec Laser 4 4-Channel FM/4 HS-322 Servos

Sailplanes:
  In a sailplane, space and weight are very important. Choose a radio with smaller size servos for all but the largest of sailplanes. Since most sailplanes use only 2 channels, a 2-channel radio is all that is needed. A sailplane with a 2-channel radio is just about the least expensive way to get into the hobby of R/C flying. If your budget allows, go ahead and get a 4-channel now and just install only two of the servos. This will give you the safety and convenience of rechargeable NiCd batteries as a bonus.

Helicopters:
  What’s the difference between a helicopter radio and an airplane radio? If you are considering trying helicopters you should not attempt to start off by using an airplane radio. Considering the overall expense and specialization, your flying success will come much quicker with the aid of a specialized helicopter radio. Some of the features may be overwhelming at first, but if you get a good beginner/intermediate radio system you will quickly realize the need for these features and learn to use them.

Controlling Your Heli
  A helicopter radio provides a separate channel for each of the five functions described below. It has special throttle-collective pitch mixing functions that are not available on airplane radios. These mixing functions make the helicopter much easier to set up and fly . Special features such as throttle hold and idle up also increase ease of flying and aerobatics. More channels may be used for other purposes - gyro switching, lights, landing gear, etc. Study the chart below to understand the movements of the sticks on a heli radio and how those movements affect the action of the helicopter.

1. THROTTLE- Moves the helicopter up and down. Transfers engine power to the spinning rotor blades and increases collective pitch to lift the helicopter.

2. COLLECTIVE PITCH- Moves the helicopter up and down. Controlled by the throttle through automatic mixing, the pitch of each of the two main rotor blades are directly proportional and change together or collectively to create the desired movement of the helicopter.
   
3. TAIL ROTOR PITCH- Turns the helicopter right or left (Yaw). This tells the helicopter which direction to face. In the neutral position, the tail rotor blades have built-in pitch, which enables it to counteract the torque of the spinning main rotor blades.
   
4. FORE-AFT CYCLIC -Tilts the helicopter forwards and backwards (Pitch). Changes the pitch of the main rotor blades in cycles, which adjusts the pitch (forward and backward tilt) of the helicopter itself. This enables the helicopter itself to fly forwards or backwards.
   
5. LEFT-RIGHT CYCLIC-- Leans the helicopter to the left and right (Roll). Acts similar to the Fore-Aft Cyclic, except in this case the helicopter leans to the right or left in order to fly in either direction. A gyro is kind of like an “automatic pilot” for the tail rotor function. Generally, the tail rotor is a touchy, difficult function to control (and the most important while learning).
   
6. GYRO- is a little black box that contains special components and circuitry to help you hold the yaw (left and right turning) position of the helicopter. Don’t fly your conventional heli without a gyro. All helicopter flyers today, from beginner to expert, use a gyro.

Great Starter Helicopter 6-Channel Systems
Futaba 6EXH 6-Channel FM Computer Radio
Tower Hobbies 6XM 6-Channel FM Computer Radio

What comes with an Air Radio System?
  Most Aircraft Radio Systems come with:
Transmitter (Tx) - The hand-held radio controller. This is the unit that sends out the commands that you input.
Receiver (Rx) - The radio unit in the airplane which receives the transmitter signal and relays the control to the servos. This is somewhat similar to the radio you may have in your family automobile, except the radio receiver in the airplane perceives commands from the transmitter, while the radio in your car perceives music from the radio station.
Servo - The electromechanical device which moves the control surfaces or throttle of the airplane according to commands from the receiver. The radio device which does the physical work inside the airplane.
Batteries - 2 and 3 channel systems generally do not come with batteries and extra Alkaline "AA" batteries will be required. However most 4 or more channel radio systems will come with NiCd rechargeable battery packs for your receiver and transmitter and will include a charger. Check the requires section of the radio system you have chosen to make sure what is included and what is not.

There Are Four Different Frequency Groups To Choose From

1. Aircraft Use Only (72 megahertz, Channels 11 - 60): This is the most popular choice for flying models. Most radios designed for model aircraft and helicopters will be available on these channels.
   
2. Surface Use Only (75 megahertz, Channels 61-90): Cars, boats, and other non-flying models must use one of these channels. Radios designed for cars/boats exclusively with a steering wheel or pistol grip control are only available on these channels.
   
3. All Uses (27 megahertz, Channel Code A1-A6): Although legal for all models, we suggest that you use 27 megahertz only for surface models. This is because of the possibility that some unseen operator may innocently be operating a surface model on the same channel within range of your model airplane which would cause interference and a possible crash.
   
4. 2.4GHz Spread Spectrum Technology One of the most exciting new breakthroughs in hobby radio technology is the use of 2.4GHz spread spectrum technology -- which gives modelers of ALL skill levels the fastest, smoothest, most accurate and most reliable control possible. Futaba's 2.4GHz FASST radio equipment in particular has advantages that greatly benefit new R/Cers. Simply by pushing a button, you link the receiver to a single transmitter -- each 2.4GHz FASST transmitter has been assigned a unique ID code at the factory. Once that link is set, the receiver responds only to that one transmitter. In addition, Futaba 2.4GHz systems never stay on a single frequency for more than two milliseconds. You never have to worry about signal conflicts, and never need to wait for an open frequency when you're eager to enjoy a day of racing or flying with other modelers!
   Note: that countries outside the United States may offer different frequency allocation schemes