That's awesum dude, I wish I had the technical ability for a hobby like that!
Well you start off slow, (Estes or Aerotech motor ejection) then you go to Cert. level one, bigger motors, most still do motor ejection. When you are comfortable, you try for Level 2, which is a knowledge test, easy, and a flight with electronics for chute deployment, which now you can fly up to a "L" engine. Then there is Level 3, you must build your rocket, document the entire build, inside and out, predict the altitude of flight, there is software for that, your rocket and plans must be inspected by two inspectors, finally you make a Level3 flight, "M" motor or larger, if you get it back in one piece, you are certified, and as it stands now, you can legally by and fly ANY motor "M" and up. M motors start at 6000ns, the Saturn V was 188,000ns which put it into the "R" motor range.
Tom