Despite its age, How to Win Friends and Influence People remains a valuable how-to guide on becoming a more likable person, doing so with a sense of wit that still reads well to this day. The lessons offered by Carnegie are timeless tips involving a bit of psychology, and a lot of human decency.
A main theme of the book is becoming more interested in other people than you are in yourself. In a traditionally self-absorbed American culture, this is a valuable reminder. What better way is there to make a positive relationship with someone besides putting their interests ahead of yours? As Carnegie puts it, "to be interesting, be interested."
The insights that he has on interpersonal conflict is also invaluable. Carnegie wisely points out that "losing an argument is to lose it, and winning it is to lose the man." Do you really "win" when you win an argument? Usually your peer will be even more reserved than before an argument, not really solving anything. Be sure to hear out their entire opinion, and never say the cursed words: "you're wrong."
For managers/business owners, he also adds some invaluable knowledge for motivating people. Some of this advice includes letting others feel like your ideas are their own, asking questions to guide them to the answer rather than delivering it to them, and pointing out your own errors before your own.
To summarize his eloquently worded book in my own words would be of use to no one, but those are the central themes that stuck out to and impacted my own worldview. The writing style of this book holds up surprisingly well considering the original version was published in 1936. It suffers from very little of the long-winded and redundant passages in some of the more traditional personal development books. His sense of humor also pervades the tone of the book, and his input on specific anecdotes helps clarify the message of the story into an easily-digestible application.
To answer the question of the article, How to Win Friends and Influence People is absolutely still worth the read today.
It is a fantastic guide for anyone, from business executive to college art majors, his tips on improving your people skills are invaluable for any interaction. To invest in yourself by reading the book, check it out here.