A few years ago at the Heritage Harvest Festival my mother-in-law got see Dr. Richard C. McDonald speak on the use of beneficial bugs and strategic plantings to organically protect your garden from some of the most troublesome garden pest. Going only by the name "Dr. Bug" McDonald uses beneficials in conjunction with a system that uses both sacrificial plants to lure bugs away from your precious crops and plants that repel various bugs.
His website is full of information, including links to countless works on growing organic broccoli.
My mother-in-law loves this guy and has a lot of fun plotting out her organic garden using some of his techniques. Check out the Farmscaping link on his site for information on what protective crops to grow where and in what season, as well as the top beneficials and the insects they go after.