The poem "Stopping by Woods on a Snowy Evening" was written in 1922 by Robert Frost. It was included in his Pulitzer Prize–winning collection New Hampshire: A Poem with Notes and Grace Notes in 1924.

The poem is set in New England in the winter. Although the particular location is not named, Frost owned and lived on a farm in Franconia, New Hampshire, which serves as the inspiration and physical setting of many of his poems.

The poem itself describes the narrator riding a horse through some woods owned by a man who lives in the village nearby. There is no farmhouse or other habitation in sight at the place where the narrator stops. The narrator describes the location as being "Between the woods and frozen lake." Thus, we can describe the setting as a path or road through a forest in New Hampshire, near a lake, during a snowy winter day. The phrase "The darkest evening of the year" implies that the precise date is the Winter Solstice (21 or 22 December), which is the day with the shortest amount of sunlight of the year in the Northern Hemisphere.

In "Stopping by Woods on a Snowy Evening," how does the speaker describe the surroundings?

The speaker is not necessarily standing, as your question suggests. More likely he has pulled up and remains seated in his sleigh while he watches the woods fill up with snow. There would not be much point in his getting out of the horse-drawn vehicle when he can see the sight just as well from where he is sitting. No doubt the horse would not shake its head to ring the harness bells if the man were standing some distance away. Tourists often stop their cars to admire a beautiful view when they are taking road trips. Typically they remain seated inside. They don't intend to stay very long, but they realize they can't really enjoy the view if their car is in motion. The speaker in Frost's poem may have another reason for remaining seated in the sleigh. If he has been traveling some distance in an open sleigh on a cold, dark night, he probably has a heavy blanket wrapped around his legs. 

The speaker specifies in the second stanza that it is the darkest evening of the year. He must mean that it is the longest night of the year, which would be December 21st, the beginning of winter, just a few days before Christmas. The setting is rural New Hampshire. According to Wikipedia:

"Stopping by Woods on a Snowy Evening" is a poem written in 1922 by Robert Frost, and published in 1923 in his New Hampshire volume. Imagery and personification are prominent in the work.

It should be noted that at that time of year and in a place with such a cold winter climate, the deciduous trees would be bare or nearly bare skeletons, like the trees in Shakespeare's Sonnet 73, which are described as follows:

That time of year thou mayst in me behold
When yellow leaves, or none, or few, do hang
Upon those boughs which shake against the cold,
Bare ruin'd choirs, where late the sweet birds sang.

The speaker would not be stopping to look at bare ruined trees. The woods he is describing must be evergreens. One of the principal crops grown in New Hampshire is evergreen trees, or Christmas trees, which are exported to the big Eastern cities. When the speaker says that he is stopping "To watch his woods fill up with snow," he must mean that the typically wide-spreading branches of the evergreens with their upright needles are catching the falling snowflakes and gradually being covered in white. This always makes a beautiful picture and is to be seen depicted every year on countless thousands of Christmas cards. It is not the ground that is filling up with snow, but the trees themselves. Soon the branches will be weighted down with as much snow as they can bear.

It is early winter. The snow is falling very softly. It may be one of the first snow storms of the year, and this would explain why the speaker stops to appreciate the sight. If it were later and there were more snow all over the landscape, the speaker would be less likely to be struck by the beauty of this scene. 

In “Stopping by the Woods on a Snowy Evening” the speaker carefully sets the scene by describing the woods.  The woods are isolated, and filling with snow and there is a light breeze.  It is evening, so it is getting dark.

This poem contains a beautiful description of the woods.  First of all, the speaker does not know for sure who the woods belong to, but he thinks he knows because the person does not live in the woods—he lives in the village.

When the speaker stops by, it is the “darkest evening of the year.” There is no farmhouse near the woods, but there is a “frozen lake.”  It is windy, but not too windy.

He gives his harness bells a shake
To ask if there is some mistake.
The only other sound's the sweep
Of easy wind and downy flake. (see first link)

The woods are described as “lovely, dark and deep” and the speaker would like to stop and look at them forever, but he has miles left to go.

This poem can be interpreted on two levels.  On the first level it is a beautiful poem about a man, a horse, and woods filled with snow.  The description of the woods is delicate and beautiful, but very simple.  The poem can also be interpreted on a physical level, describing the temptation of death as a peaceful sleep.