Steel shafts supposedly give you better feel when hitting shots. You will also feel hard shots into the ground, tree roots, etc. more and on a cold day will feel mi**** shots stinging your hands, almost like hitting a baseball off the end of the bat in cold weather.
Graphite shafts are easier on the hands, wrists, elbows and shoulders.
Regular flex would be the shaft flex (steel or graphite) for the average golfer with an average swing speed. Stiff flex is for those with higher swing speeds, like the pro's or low handicapers.
As we get older, in most cases graphite shafts in a regular flex are the way to go, and if our swing speed slows way down, you can also talk to your club fitter about "senior" flex, which is a shaft that has a whippier flex than regular.
The flex lets the club head square up at impact and give power to the shot better by unflexing according to the swing speed; senior flex will square up nicely with a very slow speed, with regular and stiff doing the same thing, just at higher swing speeds.
Just remember that swinging harder doesn't necessarily mean hitting it longer, and a golfer driving the ball a 175 yards will usually beat the guy that hits it 300 yards into the woods or water.
Enjoy your game.
So keep your head down, knees flexed, back straight, proper grip, feet spaced just right, arms straight, and then try to hit the ball...what ball...oh that little white thing...
