Even though the computer industry's primary constant is change, there are still some more "constant constants" to aid builders in component selection. Tom's Hardware Guide has been a primary resource, covering the latest technologies for over ten years. Our community Forumz members have answered individual hardware questions for nearly as long, both sources working to prevent common mistakes that might ruin a project.
Before any parts are selected, a builder should clearly understand the machine's intended function. General purpose systems that deal with such tasks as 2D games, Internet browsing and document creation, will obviously have modest hardware requirements. In contrast, high-end 3D gaming systems will require better graphics, better cooling and a larger power supply. Special applications, such as 3D model creation and home theater PC use, should also be considered - these tasks require specialized hardware.