If you don't have an air driven pin nailer, brad nailer or finish nailer, which tend to not split wood, here's a technique my grandfather taught me for driving a nail through a piece of wood that will guarantee no splits.

Cut the head off of one of the nails that you will be using. Chuck it in your electric drill and use the point of the nail as a drill bit to predrill the holes through the the wood. The hole will be sized perfectly and the wood will not split. This works especially well for thin wood strips like might be usd for holding in door glass.

Another technique to avoid splits, although not as foolproof as the above method, it to dull the point of the nail with your hammer before you nail it. Now, you will be crushing wood fibers instead of driving a wedge when you nail.