In the first section the speaker in the poem is traveling through the countryside during winter. He wants to stop and watch the snow fall, and because the owner of the land is nowhere to be seen, he knows he won't get in trouble for trespassing.
The next few lines mostly focuses on the beauty of the scene, yet he hints that perhaps all is not as perfect and beautiful as it appears with words like "darkest" and "frozen."
"To stop without a farmhouse near
Between the woods and frozen lake
The darkest evening of the year"
Then the horse shakes his harness, which jingles his bells in the silent night air. This jingling contrasts with the silence around the speaker, showing how quiet and serene this area is.
In the last few lines the speaker would like to venture into the woods, but he has obligations or a job to do. So he must be on his way. Again there is mention of "dark and deep" hinting at something darker beyond the beauty here.
The last two lines are famous ones. "And miles to go before I sleep" (repeated). The first line could refer to the journey that he must make while the second could refer to what time he has left in life. This second line ties in the darker images that are hinted at throughout the poem.