If there's an underlying theme to most of the buyers' guides you'll find here at IT Reviews, it's that whatever you're in the market to buy, the breadth of prices you'll see is really quite startling. No area demonstrates this better than keyboards for desktop PCs. We'll come to mice and gaming controllers later.

At the bottom, entry-level end of the keyboard market, you could easily pop off to a local computer fair and spend a couple of quid. Chances are you'd get a bog-standard keyboard that'll plug into the PS/2 port on the back of your PC (usually this port is colour-coded purple). At the top end of the market, though, you get firms such as Microsoft and Logitech offering deliberately deluxe models, which will happily relieve you of over £120 for a full desktop set.

So let's consider the features you're likely to need from a keyboard. Models from pre-1995 tended to have 103 keys on them, and the basic models since then have added two Windows keys to up that number to 105. The 103-key models have a bigger space bar, on the whole, but let's assume that 105 is the minimum for now.

As we've outlined, a straightforward 105-key PS/2 keyboard will set you back barely five pounds, but then you have to consider the comfort factor. It's hard to prescribe a best option here, as it's really down to individual taste and there's no substitute for giving the keyboard you want to buy a practical workout.

Consider things such as how far the keys have to travel (and that can be too much or too little) and whether they feel soft or abrasive. The ergonomics of the keyboard are important too, and this is where more expensive units usually come into their own, as they tend to be designed for maximum working comfort.

Then, if you're a traditional touch-typist, some companies will sell you a keyboard that splits the keys into two angled blocks, to enable easier typing, so you may want to take that into account as well. Non-touch-typists are advised to steer clear of such keyboards, though!

So what are your other options? Aside from opting for a USB keyboard, there's also the decision to go wireless. Here you simply plug a connector into your PC, and then the keyboard itself communicates with that connector wirelessly. There are lots of advantages here, from reduced clutter through to simply being able to take your keyboard off your desk for a while if you need a bit of extra space.

Wireless keyboards tend to work up to a couple of metres away from the connector, and while the keyboard will require a battery, generally this is only an AA or two, and they'll last for several months. One thing to note - if you like a light that tells you when Caps Lock and Number Lock are on, for instance, wireless keyboards generally don't have these, to save on power (although sometimes you'll have an LCD equivalent).

You'll also find, when you're shopping around, that most keyboards now have more than the 105 keys we discussed above, as manufacturers have got into the habit of putting quick-access buttons on their units. On top end Microsoft models, for example, you'll find keys that can get you into lots of programs at the touch of a button, that can control the volume of your music, and can get you straight at your e-mail.

It's quite common now to have a good dozen of these buttons, and generally they prove to be quite useful. Microsoft's keyboards have also given fresh functions to the Function keys (F1 to F12), meaning that if you want to use them in their traditional way, you need to activate the 'F lock' button.

Before we move onto mice, it's worth discussing a couple of novelties in the keyboard sector. Cherry, for instance, will sell you a solar-powered wireless keyboard that means you don't have to replace those batteries every few months. We weren't overly impressed with it, to be honest, and it does assume that you'll be locating your computer where light can get at it.

Then there are numerous companies who will sell you illuminated keyboards. As the name suggests, they light up when you're using them. The illumination should, in our view, be treated as a luxury, and it's best to check you're comfortable with the keyboard rather than just buying it for the lights!

One final point - it's worth trying to get a keyboard with a clip-on wrist rest, or at least buy a separate one. They might not look much, but they can help in the fight against RSI.

So, to mice. Similar parameters apply. You can pick up really old ones with two buttons that go into a serial or PS/2 port on the back of your computer, or newer ones that might have three buttons or a scroll wheel and that might require a USB connection. Whichever you choose, you need only spend less than a tenner to get your paws on a new rodent.

But that usual caveat applies. You pay bog standard prices, you generally - but not always - get bog standard devices. The features to look for in mice that can up the price are numerous. There's the scroll wheel for starters. In case you didn't already know, that allows you to scroll up and down your page just by turning the wheel.

The latest Microsoft mice allow you to move the wheel left and right as well, to scroll your page sideways. These are genuinely useful features, particularly if you use the Internet a lot or deal with long documents. Then there are balls. Old mice sensed movement through a ball, whereas more modern mice are more accurate thanks to optical sensors. You should always go for an optical mouse now, as the price differential is pretty much non-existent, they're easier to maintain and they're more accurate.

You'll also find that mice now come laden with more than a simple left and right button. Gamers in particular should look out for those that have three, four or even five buttons on board, which are all usually customisable through supplied software. Incidentally, at the extreme luxury end of the market, there's a deluxe mouse called the Razor Viper which is intended very much for hardcore gamers. Claiming extreme accuracy, it's a good £35 for the privilege!

Other things to look for? Well the point about ergonomics is equally valid, and again, you should try to make sure that you'll be comfortable using your rodent of choice. And wireless is a handy option, too, especially now that a wireless mouse can exist on a single set of batteries for around six months in some cases. Be aware, however, that the extra electronics can make a wireless mouse heavier than a standard one, which may not be to your taste.

Finally, for this guide, we'll quickly look at gaming peripherals. Ever since the PlayStation culture took hold, the PC joystick has been in decline, in favour of the gamepad. Gamepads come in all shapes and sizes, with different button configurations, wired and wireless options and varying levels of comfort. You spotting a theme, here? Many PC games support a gamepad, and cross-platform titles especially (such as sporting franchises and platform-style games) will benefit from one. Traditional joysticks are still available, but for the common PC game now, they're not usually the best option.

Fans of flight simulators will perhaps prefer a joystick, however, and here the limit is as big as your wallet. You can literally spend hundreds of pounds to get the most realistic PC flight deck going, or there are sticks that will do the job that leave you change from £50. As this is a genre that tends to attract dedicated gamers, even entry-level models don't tend to be too economical.

That doesn't quite hold true with steering wheels, though, which can greatly enhance driving games. Here, there are some decent enough budget wheels that will leave you change from £20. Where they tend to compromise is by just supplying a wheel, whereas if you spend a bit more you can get pedals thrown in too. You can also get wheels modelled on the likes of those used in Ferraris and such like, courtesy of the numerous licensing deals that are prevalent in this sector of the market.

Ultimately, whatever you're in the market for, it pays to follow the usual common sense rules; read the reviews, try to get some hands-on experience with your device of choice, and don't necessarily pick the absolute cheapest item.