PLS is right. If you’re looking for another good example, George R.R. Martin’s “Game of Thrones” series is very popular and well known for his well executed POV switches… Usually its a good idea to try to stick with ONE main character though and stick with their POV throughout the entire story unless there is absolutely no other way around it. This is especially good advice for new writers as it will give you a chance to really practice what you know and what you learn about writing and master it before you break “the rules”. 😉
If you’re not sure which character is actually your MAIN character… your protagonist… then think of them this way: Which character, of your five important characters, is the ABSOLUTE MOST IMPORTANT ONE. That character, whomever he is, is your main character and your protagonist.
When I first started writing, I used to have the same problem you do when it came to choosing a main character. I had three characters that I thought were equally important and I was convinced they ALL had to share the spotlight.
I was wrong.
I soon learned that only one character (the older brother, Tibain) was the MAIN character, and my other characters (the younger sister, Arien, and the mentor, Dakore) were supporting characters. They were important too, but not as important to the story as Tibain. Tibain was who the story was actually ABOUT. The story wouldn’t survive without him. It wouldn’t even be the same story without him. He was the most ESSENTIAL character. The one the story absolutely revolved around. Most things that happened in the story happened to him and were witnessed from his perspective, and THAT’S what made him my protagonist.
Again… read “The Fantasy Fiction Formula”. I think it will be a very big help to you. 🙂 And read LOTS AND LOTS of fantasy and science fiction books… you’ll find that by reading more and more of them, you’ll grow familiar with the genre’s style, tropes, story-formulas and so on… and through growing familiar with it, you’ll get a better handle on how it is written.