Well, your content is going to need a copywriter, and since "content is
king" on the web, for the most part, that`s an initial consideration.
Why do you think your posters will particularly interest school kids or
corporations?
I`m not "attacking" your ideas, just looking at things as if you were
walking into my office with an offer to decorate the place. I can
relate to artists, and I`m not suggesting any type of critique or
judgement on your art itself; we`re only discussing the business end of
this company you`d like to get started. :-)