It's a series of letters written by Rainer Maria Rilke who was a poet. The man writing to him was asking Rainer to look at his work and to give him advice on writing. There are no letters from the point of view of the man who wrote to Rainer, only the letters that the man received from Rainer.
The reference that I have seen often when this book has been mentioned is what Rainer says about writing. I am paraphrasing here, but he says that if you look inside yourself and ask yourself "must I write?" and if the answer is anything but a resounding yes, then you should just walk away. If the answer is yes, then you must write.
His point of view is very interesting, and the book is full of wonderful quotes about life and writing. He focuses on details of the self and of using whats around us in our work.
It's not a easy read even though it is very short and comprises 11 letters that Rainer wrote. His thoughts are esoteric and at times a little difficult to follow.
The beauty of it is, Rainer was being completely candid and open with his thoughts and feelings during this period of time. It was like reading some one's journal. I found it quite interesting.
Recommendation: Pick this up if you are interested in writing, or even following your dreams. It's so full of wisdom that I think it's worth having around to pick up again and again because I'm sure you'll come across something new each time.