How do I install a steering wheel so it is centered when the engine is in "straight-ahead" position?

There are several methods, depending on the type and model of steering. 

For mechanical rack and pinion steering, attach the cable to the engine, then center the engine and center your steering wheel. Then bolt the rack to the helm. (You may have to wiggle the steering wheel to get the gears to mesh.)

For mechanical rotary steering helms, the starting steering wheel positin when you first feed the cable into the helm determines where it will be when the steering cable is centered. To center the steering wheel properly, we suggest orienting the wheel (depending on the rotary helm installed) in the positions depicted below. These starting positions assume the helm is mounted for an ordinary starboard cable exit.

You won't have to worry about centering a steering wheel when installing hydraulic steering. Due to a small amount of "slip" or "drift" inherent in any hydraulic system, the steering wheel will not remain centered. The use of a wheel with equidistant spokes is the best solution for hydraulic steering since that type of wheel has no natural "up", "down", or "sideways" position.