The vast majority of books, both fiction and non fiction, are written in the third person point of view. This style can also be termed the "omniscient viewpoint." It puts the reader in the place of observing the characters and what they are thinking and saying. It has become popular due to the fact that this style is the easiest to read, allows writers to effectively broadcast the inner thoughts of characters and is considered to be more reader friendly than first person.
If you are just starting out in writing, it can be easy to get your point of view messed up. To use an example, when writing in the third person, it should also refer to a character as "he" or "she" never "I." Some writers have difficulty with dialogue in this point of view, but the general rule of thumb that you can follow is to write as though you are listening to your characters speak, not as though you are the person speaking. That trick will help you remain in the third person successfully.
The third person in this point of view is actually the reader. They are observing the story unfold before them. It works well across many different genres and is a style that most readers are comfortable with. Recently, more novels are being published that are written in the first person style, but reviews have been mixed.
For those just getting started in their writing career it is best to stick with tried and true methods, especially for a debut book. If you can write capably in the first person and tell a story that is not jarring to the reader, give it a try. However, for most of us, the third person point of view is definitely the best one to use.