My advice here is that copying other groups bylaws is *not* plagarization.
Your student activities office probably has a set of sample bylaws they'll suggest and I don't remember if there is a sample set of bylaws in the extension packet, but the Standard Chapter Articles of Association give a good feeling for what you have to fit in.
As for other sources, just good Alpha Phi Omega and bylaws. My guess is that dozens of chapters have their chapter bylaws online. Most of them have things added that work specifically for their chapter, so if chapter 1 has A & B in their bylaws and chapter 2 has A&C in their bylaws, you are much better off with just A than trying to make A, B & C work.
Officers: Slots that will naturally exist and that will be expected by the time you get to 15 or so people are President, service vice president, membership vice president, treasurer and secretary. Someone who knows Roberts would make a good Sgt @ Arms or Parlimentarian (My advice is pick one title or the other, you probably don't need both until you get *much* larger (60?)). Also, make whoever actually owns a camera the Historian. Pictures are great to include in charter applications and looking at what you've done helps with fellowship.