Planning

Budget

You budget is an important thing to get figured out early on because it will impact a lot of your decisions. For instance, if you're looking for a bottom of the barrel $300 computer then you might be better off looking for discount prebuilt computer. This is because the operating system is a good portion of your cost, and large manufacturers get a big discount because they buy in bulk. The actual parts cost of a custom computer will probably always be cheaper, but because the big manufacturers like Dell only pay about $20 per copy of Windows then they can usually beat the price of really cheap computers. The higher your price range though, the larger the savings over a comparable commercial computers.

Peripherals are another important thing to consider when deciding on your budget. Decide if you are going to need a new set of speakers for instance. A new flat screen monitor is $150-$200. If you don't mind the added weight, an old tube screen monitor can be picked up for a little of nothing. New speakers can be cheap, but you might want some nicer ones. A great pair of computer speakers can be had for around $50. A good keyboard and mouse combo will be somewhere around $20-$30. Keep your budget in mind when selecting parts later. Below is a good breakdown for a pretty good $800 computer

$125 – Motherboard
$175 – 22” Widescreen Monitor
$40 – Power Supply
$70 – Good Graphics Card
$170 – Quad Core Processor
$50 – Midrange Speaker Set
$50 – Hard Drive
$30 – DVD Burner
$70 – Case
$20 – Keyboard + Mouse

Form Factor

A big component of what parts you can pick for your computer is what size of computer you would like to build. The size of the computer is generally determined by the form factor of the motherboard it is the biggest component of the computer. Form factor is an agreed upon specification for the size and shape of components. Both the motherboard and the case have to follow an established form factor standard so that they work together. A lot of people want a small computer, and this is an important thing to decide right off. Personally I would not try to build a small computer for my first time because they can be cramped to work in, especially if you have big hands. In addition they will limit the components you can pick for the computer. Be aware that depending on the case you pick your PCI cards might also be half height. This means that the computer will be much thinner, but it will limit your selection of expansion cards and future upgradability because the expansion cards will only be half as tall. Below is a diagram showing standard motherboard sizes. Micro-ATX isn't difficult to accommodate, but anything smaller and things can become pretty complicated quickly.

Purpose

Before you dive in it's also a good idea to have in mind what you are going to be using the computer for. Will the computer be a gaming rig or simply a workstation? Do you plan on doing a lot of video editing, or just surfing the net? Below is a small table outlining a general idea of how you would balance the quality of various components for your various needs.

Type	Graphics	RAM	Processing
Gaming	High	Medium	Medium-High
Video Editing	Medium-Low	Medium	High
Internet/Word Processing	Low	Medium-Low	Low
Multi-Tasking	Low	High	Medium
CAD/Drafting	High	Medium-High	High
Graphic Designer	Medium	Medium	High