Where does everyone get game info from?

I see how people know info like item stacking but where do they get the information from? As much as I enjoy this site and everyone's help, I'd prefer to get the information myself. Is there a site from the company posting this stuff?

Datamining/Twitter/Forums.

Data miners are literally accessing everything a game contains. All the particles,light effects, map files, models. What not

Not sure what u mean. Do you mean like how people figure out how items work with the same or other items like two void blades on the same team or how gem of isolation and frost bound hammer work with each other when built of freya; this what you mean by item stacking?

Yea. How do people know deep, info like that is what im wondering.

For the most part, this information just kind of floats around at the higher tiers of the competitive scene and becomes common knowledge up there. If you actually follow any competitive player who makes it their job to understand all of these facets of min/maxing, you'll learn a few things. Like how currently, buying a Death's Toll+Rank 1 Boots+Mana Potion is considered to be the ideal starting build for any physical ranged.

I get most of my advanced knowledge from looking through HiRez's official forum. There are experienced players who frequent that place, and they will dissect and examine every aspect of a god or item to determine how good they are. Several of them even do their own experimenting and math to come to their conclusions, and it's how they've come to learn things like how two Voidblade auras from the same team won't stack.