Similarly, if you're working with large graphic files, especially video, a suitable graphics card is essential, as is a fast processor and adequate RAM memory. (RAM is relatively cheap to buy, so look at a minimum of 512Mb for still images and 1Gb for movies) Most digital imaging programs will have multiple editing windows or palettes. The larger the monitor, the more windows can be kept open and the larger the work area. A 17-inch screen should be considered the minimum but if the budget allows, go for 19-inch.
Standardise wherever possible. Whether it's hardware, printing consumables or storage devices such as memory cards, the less variety the better.
Standardisation means that inkjet cartridges, for instance, can be bought in bulk and equipment can be interchanged and maintained more easily. A camera that can't be used because there's not a suitable memory card is a wasted resource.
Free up resources. Intelligent management of memory cards and card readers avoids time wasted downloading from camera to computer, cuts down on battery use and ensures that the camera is available for use.
Don't run out of USB ports. USB (universal serial bus) has rapidly established itself as the most common communication protocol between digital devices. Scanner, keyboard, mouse, camera, printer, memory stick; chances are it'll have a USB connection. Make a multi-port powered hub one of your first purchases.
Supervise the printer. Kids love to see their work in print but ink cartridges and specialist paper costs can sprial. Print media is likely to be one of the most expensive resources in a classroom suite.
Establish a long-term strategy. Technology sings a siren song whose three most repeated words are "bigger", "newer" and "faster". Wherever possible consult with colleagues from other schools who have been through this process before.