Many of the suggestions on this list are good but many do not take into account earth bulge, fresnel zone, refraction and atmospherics. Typically these factors are not an issue for pretty short distances such as less than a couple of miles. But longer distances things like earth bulge can be an issue. For instance, at 21.5 miles, the earth will bulge up 60 feet. At this same distance, the fresnel zone will be about 110 feet in radius. For a flat terrain, this means that you need to have a tower height on both ends of 170 feet. Just having LOS may not guarantee that the path will work.
Tim -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
