There are some very good teaching professionals on the Internet giving some very solid advice about the fundamentals of the golf swing. Many of these teachers have been on the lesson tee for decades helping amateur golfers of all skill levels.
But it seems like there are also zillions of videos and advice programs that suggest you take a hint from one of the leading Tour pros and how they're swinging. Or there is simply stuff out there that can hurt your swing -- and you. Remember, you are not a pro and if what you're doing hurts ... it's wrong!
Find a pro you can trust, that is actually helping your game. Stick to the fundamentals.