All of the hardware components on a PC connect directly into the motherboard so great care should be taken to first choose which type of CPU, Memory and Graphics Card you want. This will make the task of choosing one much easier.

All modern motherboards should be able to take DDR Memory, have at least 4x USB 2 ports, an LAN/Ethernet port(for home networking) and a built in sound card. Some will even have on board graphics chips so you could save yourself money by not installing a new graphics card straight away.