The main character, Holden Caulfield, is a confused teen who just got kicked out of another boarding school. Before facing his parents' wrath, he gallivants throughout New York City for a few days to blow off some steam. But I didn't find Holden's exploits interesting - I was bored to sleep most nights while I was trying to read this book.
There was one insight that Holden offered that I did find very poignant, especially since it was written by Salinger in the early 1950s: "If you had a million years to do it in, you couldn't rub out even half the f*&% you signs in the world." In both a literal and figurative sense, Holden is correct. There's always going to be another person who wants to flip the bird at the world, but you can't let that consume you or you'll spend your life fighting a losing battle. Instead, just make sure you're not the one sending out the F yous .