When building your own computer one part was always a mystery to me: the motherboard. Picking a CPU/GPU/memory is easy- you just figure out where the various chips are in the low end to high end scale, do a little market research on what current games demand, and pick the parts from their respective continuums of low-to-high-end models.

A mother board is more complicated though. Its features are not as obvious as "this motherboard is faster than that motherboard". Now you need to deal with part compatibilities, bus speeds, maybe power management stuff, etc.

I'm interested in a short guide for selecting a motherboard, especially- what pitfalls to avoid (for example, can bus speed become a bottleneck?).

To clarify: I'm not looking for motherboard recommendations. I'm looking for guidance regarding how to evaluate the fitness of a motherboard given the rest of the computer parts.