In recent years Arches National Park has become a well known and very popular almost year round.  The edge of the bowl looking down at Delicate Arch can have as many as 100 eager photographers, along with a few souls who will likely sit in the arch just as the sun is setting.  One way to avoid this is to visit in the winter.  However, at this time of year the sun is so far south that the northern (classic) side of the arch is not illuminated at sunset.  In spite of this, silhouette shots can work out nicely if there are good clouds illuminated underneath when the sun goes down.  The sun also rises well south of the La Sal mountains in winter, and so illuminates the south side of Delicate Arch in the early morning.  It is very much worth getting up an hour before day break and hiking up to the high overlook on the next ridge south of the arch.  This ridge is accessed by following the main trail up to Delicate Arch, and diverting to the right as you get up to about 200 yards from the standard viewpoint.  Winter is also recommended because the campground will probably not be full, and since the sun is low in the sky, there are longer periods of good contrasty light. Other recommended photo ops are North Windows at sunrise, Balanced Rock at sunset, and Double-O Arch at sunset.  The back country of Arches has a number of exciting, but remote and difficult (i.e. technical) canyons to explore.  Refs.  For non-backcountry hiking the park maps are adequate, and the trails are pretty obvious.