You might have some luck reading the information over at the Taken In Hand site http://www.takeninhand.com/

Not sure if it would be your cup of tea, but it does have a lot of articles from a "less weird" perspective than a lot of bdsm sites, and has a lot of advice for people like you who want to make a change in their relationship but don't feel naturally dominant. I think it might be a good place for you to start