I started questioning monogamy as early as high school, and that was basically before the Internet. It was extremely difficult to find out anything about non-traditional relationships, and I certainly couldn't find anything online that would lead me to real life people. It wasn't until I was in university that I discovered sites like Adult Friend Finder that would lead us to people to hook up with for sex. It wasn't until Facebook that I discovered people I could hook up with strictly for conversations about sex and relationships.
If you're turning the idea of swinging or poly over in your head, online research and reading articles and message boards are great, but in person discussions are definitely where I've learned the most. Try searching your local city for a a message board where you can learn if there is a Facebook group, as they do tend to be hidden or secret groups for obvious reasons.
There are a number of local Facebook groups for poly people in my city, and many of them hold discussion nights or mingling nights, specifically meant for chatting, educating new people about poly, etc.
There are a few people in the poly Facebook group I'm in that I look up to as my poly guides in a way. They've directed me to excellent resources about specific poly issues, like couple privilege, that are very relevant to me. Sometimes, you just need someone to talk to, face to face, when you're facing issues that are scary or exciting and online doesn't always cut it.