The exchanges all have some very basic information freely available. This even includes some trading strategies. There may be a small amount of hype in what they say, but generally, the information is good.
The problem with information you get outside of the exchanges is all too often filled with false claims, slanted to whatever the person is selling. Traders are continually bombarded in magazines, emails and the general media with claims of making huge amounts of money, just by purchasing whatever the seller has to sell.
There is good stuff out there. I know because we try to place honest and truthful information on our own website. However the majority of what is out there is not worth the price you pay.