I want to use it outdoors!
Look for a VHF radio. Something like the Icom IC-F3002, Kenwood TK2302, Mitex Sport, or Motorola DP1400 are great standard models. If you want something more durable in adverse weather conditions or dirty environments, look for a higher IP rated model such as the Icom IC-F1000. This is an ideal option for the smaller budget. VHF radios require a license but this has been made very easy with OfCom's Simple UK Business Light License option. This costs just £75 for 5 years and covers you for any number of radios. The Mitex Sport is programmed to these frequencies already so you can just fill in the form included in the box and you're all set to go.
I want to use it inside!
Look for a UHF radio. A PMR446 radio is adequate for a small building such as a shop or small office. The HYT Power446, Icom IC-F4029SDR, Kenwood TK3501T, Mitex PMR446 or Motorola XT420 are ideal options. If there are a lot of floors, concrete or steel structures then a licensed radio will be needed. The Icom IC-4002, Kenwood TK-3000, Mitex General, or Motorola DP1400 are all excellent options which are kinder to the pocket. Again there is an easy license option as mentioned above.
Do I need to go Digital?
This really depends on your budget and your environment. The main advantage of digital is that it gives you crystal clear audio even in the noisiest of environments, right to the edge of range. They have more features available than analogue radios such as text messaging, and the battery usage time is much longer. But this all comes at an added price, so if you're just looking for simple everyday communications it's probably not for you. If you're in a busy warehouse, pub or club, you may well find digital a worthwhile investment. Digital radios are available as Licensed and License Free - which one you choose will depend on how far you need to reach, and the environment you want to use it in.
License Free or Licensed?
Range! The question on everybody's lips when purchasing a radio - how far will it reach? A license free radio is only 0.5Watt power and although some manufacturers stipulate a range of up to 10km on some 446 radios, this often leads to disappointment. Think "line of sight". If you have any obstacle between you and the other radio the signal has to push through this, weakening as it goes. The more obstacles, the weaker the signal. You could be in a completely open field with a license free radio and reach around 1km, but then put a wall or a few trees in your way and you'll be lucky to reach half that with the same radio. Vehicles, concrete, steel, even electrical signals can interfere with range, so you need to assess your environment before considering which power option you will need. As a general guide - License Free will give you half a mile at best, Licensed can give you around 2 miles or more depending on the environment.