It's been a while, but let me see what I can still remember about it. It sticks in my mind because it was the first time most of us had seen the word 'fuck' in an assigned text - half of the class was snickering and the other half was in shock. The main character uses it a lot, but I don't think the story would have as much impact if it was sanitized.
Holden Caulfield is a guy who hates 'phonies'. This includes most of the 'establishment' (teachers, parents, cops, etc.) There are a few that he respects, but for the most part, he's your standard Angry Young Man. He also sort of sees himself as a 'protector' figure. The title comes from a dream he relates, where he's standing in a field of tall rye-grass (I want to say that the dream was triggered by the song 'Comin' Through the Rye') and there are children playing in the field. Only there's a cliff at the edge of the field, and his role is to catch the kids before they run off it. It's that 'calling' that probably keeps him from being a total delinquent, although he does drop out of school at one point.