I might try to get someone to write an article about you rather than advertising. Print advertising can be iffy depending on the publication, circulation, readership, etc. It might be wiser to feel your way around before spending the money it takes for an ad.
Business cards, however, are a must. Don't skimp on them. Put your best piece in full color if you can.
I print flyers and distribute them at my booth when I do shows - they can be handy.
You will probably also want some sort of website representation either through SOG or your own site.
Hope that helps!