If you want to be educated, I'd suggest spending a lot of time perusing this thread http://www.polyamory.com/forum/showthread.php?t=1096
Plenty of good websites on there where people have written up comprehensive FAQ's and articles about different poly topics, and Reading a book or two never hurts. "Opening Up
" would be my recommendation (there may be one more useful for a person who is currently single and not going from a mono couple >> poly couple, I'm not sure, but it would help you see all the variants of poly, and has a lot of great discussion topics.)
I don't think poly is more risky, but it might be if you think in the future you want to settle down into a monogamous relationship, as in if you love with her, or some other poly person in the future, you're going to have to break up with them to have monogamy, which could hurt both you and them.
Have you met her other partner(s)? That can help tell if you'll be comfortable with this. If she starts dating you and then starts dating somebody else too does that trigger any really strong negative feelings about the hypothetical new partner? If you start dating how many times a week do you think you want to see her, and can she provide that?
Those are my ideas to throw out at the moment to see if you've thought about them. Hmm except for - can you be more specific about what you don't fully understand about polyamory? If you can explain what you mean you might be more useful responses to that bit.