Well, use your normal bridle, I like to take off the reins alltogether so they are out of the way, but I know that alot of people prefer to twist them and loop them through the throatlatch (I'll try to find a picture so that makes more sense). For the lunge line, I put the snap through the inside bit ring, over the head and clip it to the outside bit ring (you have to change it every time you change rein. That method offers more control if your horse likes to buck/take off. Hold the line so that it is as long as posible, so that he can be on a nice big circle (while you are doing this, make sure he stays out and does not step on the line. Stand twoards his hindquarters so that he doesn't change rein. Hold the line in your right hand if he is traveling to the right and in your left to the left and the whip in your other hand, trailing behind you, and only hold it out if he doesn't respond to your voice or he starts to cut into the circle. You can also shake the line slightly to get him out of the circle. Make your voice commands strong, simple and clear, that way you don't confuse him. When you ask for a down transition, make your voice softer at the end and if he doesn't respond to the voice, pull slightly on the line, and if he still doesn't respond, use a stronger tug. If you have to drop the whip and pick it up again once he stops. When you give the word for an upward transition, make your voice strong and energetic, and try not to cluck alot, that gets confusing.
--Good Luck!! : )
EDIT: I found a link to a site that is all about lunging and gives tips if you sign up with your email:
http://www.horsetrainingsuccess.com/