Mike finishes up lacing the 32 spoke rear wheel by lacing the non-drive side spokes. Note the parallel spokes that connect on each side of the valve hole. By now you might need to use a spoke wrench, screwdriver or nipple driver to help get the nipples on the spokes.
At this point, there is spoke in every other hole in the rim. All the exposed holes should be facing the non-drive side of the rim. When lacing the non-drive side, start with the "Innies" or spokes laced toward the inside of the hub. These spokes will be laced into the larger gap created by the laced spokes.The gap acts as self fulfilling prophecy, only allowing spokes that are inserted into the correct holes to make it into the large gap. Placing the spokes in the large gap allows you to actually move the spoke and guide it to the correct hole on the rim.
Now that we have laced the 3rd set of eight spokes as innies on the non-drive side of the hub we need to locate the valve hole on the rim and the existing laced spoke next to the valve hole. You follow that spoke up to the hub, then select the spoke on the non-drive side that is opposite where the drive-side valve spoke connects to the hub. Once you find the opposite spoke, lace that spoke to the remaining empty hole next to the valve stem hole. This will create the gap between the spokes at the valve hole to allow for easy pump access to the valve.
Now the wheel starts to take shape, and you can use a nipple driver, spoke wrench or screw driver to start threading the nipples on. A screw driver works great for getting the nipples started, but you will need a spoke wrench once the spokes are threaded all the way into the nipples. So we continue with our pattern of lacing every fourth hole, or skipping three from where the first spoke was placed. After finishing that set, place the last set of spokes as "outies". Hopefully it is obvious where they go. If it isn't you might have done something wrong. You simple drop these spokes into the remaining holes on the non-drive side of the hub. Lace the last eight spokes "three-cross" going "over, over, under" the spokes that have already been laced. Make sure not to scratch your rim.
Check to make sure that you have parallel spokes at the valve hole and that all your spokes are going "over, over, under"! If you forget to go under and the spokes do not touch, it will weaken the wheel. When the spokes touch it strengthens the wheel. The last step is to true the wheel.