I would argue that, yes, you do in fact need either a book or a teacher. Meditation practices and traditions didn't spontaneously develop in a vacuum, they were created in the context of spiritual traditions such as Buddhism. Non-attachment and no-self are very difficult concepts, but they are the aim of meditation! Without a good teacher (or at least, a good book), meditation can lead to some dark places.

Edit: Of course you are correct that the actual technique is very simple and can be explained in a few sentences. But there is much more to it than that - how do you process the results? That's what you need a book/teacher/help for.