Around four years ago, big-screen TVs cost more than £2,000 and high definition TV (HD TV) seemed like a pipe dream for UK telly-watchers.

But now HD is being beamed and streamed from satellites and cable networks - HD TV broadcasts have even been tested via the Freeview service.

Better still, new Blu-ray and HD DVD players are opening up HD movies to the SD (standard definition) generation. While games on both the PlayStation 3 and Xbox 360 can be played in glorious high-definition.

Want to get in on the act? Practically all new TVs are HD-ready and you don't have to pay over the odds for them. But what exactly should you look for? Where should you start?

Choose a suitable size of HD TV

If you're replacing a bulky old CRT TV then the slimness of many new models means that you can get a bigger screen for your money. An LCD TV is the only real option if you're looking at sizes up to 40 inches.

Most experts agree, however, that plasma technology offers far better pictures at 40-50 inch sizes and upwards. For anything larger consider a rear-projection TV or standalone home cinema projector plus screen. View our latest TV and projector reviews here .

Where is your HD TV going to go?

People often think about wall-mounting their high-definition TVs but few actually do it. For a start, brackets must go on a load bearing wall. The typically small British living room means that above the mantlepiece is too high, causing neck strain.

To be honest, it's better (and cheaper) to buy a good table stand. For HD viewing, the ideal seating distance is about twice the screen's width (eg: 2m from a 42in TV).

What peripherals will you need?

Audio is an important part of the HD experience, so don't forget to add a suitably powerful surround sound system. It's harder to get a good speaker arrangement if the TV's in a corner, so avoid that if possible. Also, remember that to see HD you'll need to attach a separate device HD digibox, next-gen disc player, PC or high-end games console.

Why is HDMI important

The default connection for HD is HDMI (High Definition Multimedia Interface) - think of it as a next-generation SCART connection. Any HD-ready TV will have at least one HDMI port. Switch boxes and amps can cope with multiple connections but it helps to have a spare HDMI on the TV too for future expandability. In short: avoid HD sets with only one HDMI port.

The latest standard of HDMI is v1.3 , which is only available on the newest and best products. It offers further improvements to colour and audio syncing, and it's relatively future-proofed. To take advantage of this, your TV, cable, player or set-top box should all be v1.3 compliant.

Know your 'i' from your 'p'

The basic HD spec gives 720 horizontal picture lines, usually as 1024 x 720 pixels. This can be shown on screen at once in what's called progressive scan (eg: 720p). It's favoured by home cinema buffs as it's closer to the cinematic experience and can make moving shots appear more solid.

A different technique is interlacing, where alternate lines are displayed a fraction of a second apart. It gives the impression of more detail (ie: 1080 lines) but this 1080i approach means all lines aren't on-screen at once and moving shots can look less clean.

Stepping up to 1080p

The current state-of-the-art technology delivers 1080 lines in progressive scan, or 1080p (1920 x 1080 pixels). HD TV is not broadcast at this quality but this resolution features in most Blu-ray, HD DVD players and some DVD machines that upscale to simulate HD quality.

Currently you'll pay more for the privilege of 1080p visuals and the benefits are only really noticeable on screens that are at least 50 inches wide.

How 24fps could be the next big thing

Another twist to the high-def tale is 24 frames-per-second display (aka 24Hz) available with a few 1080p players and TVs. It's designed to match the original frame rate seen in cinemas, though it's usually multiplied neatly into 72Hz or 120Hz to reduce TV flicker. It can remove timing distortions or the sometimes jerky movement caused by conversion from film to disc.

Our top tips for buying an HD TV

  1. HD is best suited for screens measuring 42 inches or more. If you're splashing out on some HD gear (and you've got the space), then think BIG!
  2. LCDs might be rivalling plasma at larger sizes now but plasma still offers a better picture quality for the money. Beware: there's no such thing as a good, cheap plasma. If a price sounds too good to be true, then it is too good to be true.
  3. Don't forget that an HD-ready set won't show true high-definition pictures without a suitable peripheral device attached - Sky HD box, Virgin V-Plus box, HD DVD or Blu-ray player, PlayStation 3 or Xbox 360.
  4. HDMI is the main connection you'll need for an HD TV. The best TVs offer more than one. Don't skimp on the cost of the cable either. Despite working in the digital domain, decent HDMI cables noticeably boost performance.
  5. Bear in mind that 720p/1080i is an entry-level HD resolution. Advanced 1080p and 24fps features are already appearing in the latest players and TVs.

Words by: Ian Calcutt