Nowadays it’s almost impossible to imagine our life without books. Perhaps, there are more books on our planet than men alive.Long before the invention of printing people valued books as treasure troves of the human knowledge and experience. Hand — written manuscripts took months of writing and were collected by and kept in monasteries with utmost care. We can distinguish books between three classes of them.Firstly, books on different branches of knowledge, works by brilliant minds of mankind. Secondly, textbooks, reference books and numerous dictionaries. And at last, books of all kinds and genres to read at leisure.Classics should be taken a little at a time. One’s understanding of books by Tolstoy and Dostoyevsky, Mopassan and Balzak depends on one’s age and experience.Serious books are to be read conscientiously and maybe more than once. To a thinking reader they will provide new food for thought every time he rereads it. Many people indulge in reading science fiction, fantasy or detective stories. Of course, there are some advantages and disadvantages of this kind of literature, often reffered to as «easy reading».As for me, good science fiction and fantasy develop imagination, logical thinking, broader one’s outlook.The same could be said in favour of detective stories. They reveal such minute details of everyday life in this or that particular country that are of greatest interest for a curious reader. The masterpieces of this genre by Sir Arthur Conan Doyle, Agatha Christie and others, show the depths of psychological analysis, the insight into the human nature.As an old saying goes, man cannot live on bread alone. Books are the source of knowledge and the means of self — perfection. Sometimes it is difficult to solve some problems in life. I think that books can help us. Books must be our friends during all our life.