Here is a showmanship video. Pay attention to the part where she sets her horse up for the judge. This is called quartering, and it's the proper thing to do. Pretend your horse is divided along his spine, and through the girth area. When the judge is in front of the girth area, you should be on the opposite side, and when he/she is behind the girth, you should be on the same side.
Walk, trot, whoa, back, pivot, and stand are the skills your horse needs for showmanship. When you give a cue, your horse should respond right away. He should also walk, trot and stop straight. Sometimes patterns call for circles or partial circles, too. I've seen a lot of patterns lately that call for backing around a cone.
When you approach the judge to set up, make sure you leave at least an arm's length between the horse's nose and the judge. And make sure the horse is in front of the judge, not you.
For horsemanship, make sure your horse is responsive to your cues, and does not toss his head or swish his tail too much. He should take the proper leads, travel in a straight line or a correct circle. He should at least be able to do a simple lead change. He should be able to pivot in either direction and back in a straight line and around a cone (in either direction). You should also be able to control the speed of his trot and lope with quiet cues.
These are just some things to work on, and I'm always working on at least two of them. For example, my gelding has forgotten how to back around a cone.
Both of these events are judged on you, and how you present your horse. So, have your horse clean and shiny, paint his hooves. If his mane is short, band it. If it's long and you don't want to cut or pull it, make sure it is tangle free. Clip the bridle path, muzzle, eyes, ears (if it's not too cold or he lives inside) and fetlocks. I clip from the fetlock down to the hoof, up the back of the fetlock, and down the back of the leg. Put a little shine on his eyes and muzzle. Make sure all your tack fits well and is clean. Your attire is just as important. Your clothes should fit well, be clean and pressed. Your boots should be shined and your hat should be clean and well shaped. Your makeup should be more dramatic than what you normally wear in order to show from under your hat.
For small shows, you don't need to go all out on the presentation thing, but I usually do because it's good practice. Sorry for the novel, I can really get going sometimes.