Beginner students usually starts in 6th grade, but there are a large amount of parents that have their student start on the instrument with summer lessons before 6th grade begins. I wrote a supplement titled The Mighty Five which focuses solely on the trombone/euphonium. We work out of this supplement and I help the student with any difficult assignments from their band class.
My goal for beginners is to focus, from day one, on a good foundation. Bad habits are created in an instant, but take weeks to eliminate. There is a correct and incorrect path to take for every decision you make when playing an instrument. My goal is to keep the students on the correct path.