Both Upper and Lower Antelope Canyon in Page are spectacular and should be seen while in this area. To get to either canyon from Page take 89 local (main street) to Coppermine Road, follow Coppermine Road to Highway 98 and make a left. Take 98 about 2.5 miles to the sign for Upper Antelope Canyon on the right. To get to Lower Antelope make a left on 222 just beyond the entrance for Upper Antelope Canyon. Entrance fees for either are about $30 per person, more for a photographers permit ($48?).
If you visit Upper Antelope Canyon you should go during the morning as this is when the ray of light enters the canyon. I have been to Lower Canyon in both the morning and afternoon and didn't see much difference in conditions, although I have heard that morning is better. Lower Antelope also gets rays of light during part of the year. For either canyon you should get the "Photographers Pass" which will allow you to stay in the Canyon longer (two hours). If you stay longer than two hours you will need to pay an additional hourly rate. You must have a tripod with you to take the Photographers Pass, no exceptions.
After paying for your ticket to Upper Antelope you are driven three miles down a wash in an open vehicle to the mouth of the canyon. On the right side of the wash there is a canyon called Rattlesnake Canyon (http://eujingoh.com/pics/antelopecanyon/index.html) which is rarely visited, I haven't been there yet. You should also bring a tripod and a rain cover for your camera, especially on a windy day when sand will be constantly blowing into the canyon from above. A tall tripod will help with some compositions, also a tripod which allows the center column to move in any direction can help (Gitzo Explorer series). A small flashlight will also help. Flashes are worthless in the canyon. Normal focal lengths would be from 24-100 mm. In Upper Antelope the best light is often near the top so you'll be working more toward the longer end of the range. In either slot you might occasionally want to go wider than 24mm. Bracket heavily and use spot metering. Spot meter against the brightest part of the image.
Lower Antelope is about 1/4 mile long and ends abruptly with a 100 foot drop off. The canyon continues on to Lake Powell but never slots up again after the drop. In Lower Antelope Canyon there are some ladders to climb so bring a light pack. When you get to the drop off in Lower Antelope you can either exit the canyon by climbing up a ladder and then rim walk back to your car, or you can backtrack up the canyon. Upper Antelope Canyon is only 100 yards long and is much more crowded, but generally gets better color. Both canyons are closed after heavy rains or when rain is threatening.
At the Upper Antelope parking area you can also get a pass for Waterholes Canyon for $12. Waterholes is appropriately named, it is usually wet and may be muddy. The one time I was there I ran into a midget faded rattlesnake which was situated right where I needed to place my hand to climb up a small ledge so - hike ended.
The google map below shows how close the parking is for the two parts of the canyon, both can be done in one day. Do not bother with either if the sky is overcast, for these canyons everything is about light.
To view the map larger please click on the box in the upper right corner of the map.