I only started really getting into comics and considering myself a fan at about age 12. That being said, I've been reading comics since I was a kid...maybe 8 or 9?
This. I don't remember when I started but its probably 7-8, I used to read Phantom, Archie and Tin Tin, became a fan of the main stream comic books like Spider-Man and Batman during 11-12.
I was poor as a kid and didnt know what comics were until I was a pre teen but still didnt understand what they were about. I didnt know that Superman was a comic book character till I was 14. I started reading when I was 17, just books from the library. The first monthly series I bought was Kick Ass 2 and because of the new 52 it gave me a place to start. I started with less than 10 now Im up to 20 something.