I am/was in a simalar situation with my girlfriend (lavender), i found its a bit of give and receve, let her know of your feelings and give her some backgroung information, nothing too deep, just so she understands a it beyond "pain" as its a common missconseption that BDSM s all about Pain, eg, i enjoy the bondage and humiliation side of it where as someone else may enjoy a stern cane (this you will find out with expermentation, even if you think you know what you like now, you may be supprised you find you like someithing else more). As i was saying its the whole give and receve thing, find something she loves you doing to her (oral etc...) and maybe she will be more inclined to dominate you occasionally.
-Dont push her or you wont get anything, trust me on that one.
-Try not to demand it all the time, this may deter her.
-Do start small, expeiment a little, she may find she likes doing something
-DO show her this site, some of the knowledge base and my BDSM life will answer some of her questions, (im sure she'll have many)

You're in a good position as i wish i found this site whan i got into BDSM, as what i know i have found out the hard way, although find your own things because part of the fun of it all is the serching inside your self and your partener, and the expermentation ohhh the experimantation. Just remember it may take a while, so good luck and hope the two of you come to some agreemant as everyone i have spoken to who's in to the scene are friendly and inteligent people.

hope my advice helps, Subdude05