Well that depends on how experienced you are with flying them. There are ones for complete beginners such as the very simple to use and extremely tough Syma S107 right up to something like the Walkera 5-6 Genius Chopper.
Visit Red5 for some of the cheapest and best prices available or continue down the page to find a selection of the best r/c helicopters available.
The great thing about mini helicopters is that they can be used both indoor and out making them great toys for all year round. The smallest of the bunch, the Picoo Z weighs in at just 10g and is officially the smallest one available at the moment. Its also great fun to fly and very easy to control making it the perfect model for the beginners and at less than £20 it's hardly going to break the bank!
Red5 the online gadget retailer have a selection of radio controller helicopters available on their site and by using discount code 'NEWBIE5' (expiry 03/01/12) you can get a further 7% off their already great prices.
A lot easy than you may think. Usually ready to fly straight out of the box and very easy to learn how to fly, take a look at the videos on the individual pages to get a better idea on how each helicopter works. Some onlt have basic functions such which make them easier to fly while others are a lot more complex and take more practice to learn how to fly correctly