Control
R/C helicopters are available with varying levels of flight control. 'Toy' R/C helicopters are usually controlled using two channels. This means that the pilot has control over the throttle and turning movement alone. 'Hobby' grade beginners models are controlled using four channels, these allow the pilot full control of the model and are a step towards flying more advanced outdoor models.
Stability
A good beginners model is stable in flight. If the helicopter is unstable, then controlling the model becomes very difficult. The most stable and therefore easiest models to fly are those with coaxial main rotors. These models have two main rotors one above the other.
Flying Site
If your flying site is indoors a small, light model, made from plastics and foams will be least likely to damage you,itself or your room when it crashes.
If your flying site is outside, a bigger model will cope better with weather conditions and increased range of flying.