I'm new and have a question.

So, I've known of Warhammer since 1996 when I watched my older brother play in the basement with his friends. I, personally, have never really liked Warhammer until recently when a friend gifted me "Warhammer 40,000: Space Marine" and demanded I play it. I did and I now realize how much of an idiot I am for not loving this off rip.

Who do I learn about first or what do I learn about first? Some places say to introduce myself with the Horus Heresy while others tell me to get into Choas Gate. Where is the most "definitive birth" story of the entire franchise? Like a good entering point for someone so late to the game.

Man, and to think this was a moderator approved post.