Though the job market is pretty healthy these days, there's a lot of competition out there. One way to get a leg up, therefore, is to present an outstanding resume, and knowing what mistakes to avoid will help in this regard. Here are four things that are almost guaranteed to turn hiring managers off, so keep them in mind when crafting your resume.The first thing hiring managers will see on your resume is your opening summary, and getting that snippet wrong could cause that document to get rejected in the blink of an eye.