Pretty simple really.
Some form of conductive material as high as possible, with a direct path to ground.
Get one of them really long copper rods and hammer it as deep into the ground as possible, then get some of that heavy 2 guage welding cable and run it between your conductive pole and your earth ground. Depending on the size of your building, you may need more than one ground rod.
Think of your conductive pole as the center of a TeePee. Anything inside the "skirt" should be protected.
Lightning does not have to be a direct hit to cause damage, so you want to direct it AWAY from your building. Put your conductive pole far enough away, but HIGH ENOUGH that your still within the "protection area".
Also, lightning protection systems actually INCREASE your chance of being hit, but the concept is to direct the strike AWAY from your house/equipment.
DO a GOOGLE and you will find TONS of reading.