Canyonlands is on Utah SR 313 which is accessible from US 191 near Moab, Utah.
I read on a photographer's blog that you should be thankful if you get a partially cloudy day at the park. You can shoot decent shots even in the mid-day. He was right!
Canyonlands National Park is not as popular as its next door neighbor, Arches National Park. During the daytime there were only a few tour bus groups and plenty of easy access to many desirable photo sites. At Arches the parking lots can be filled and the more interesting rock formations crawling with tourists.