hearing what other people have to say (i.e. reading books) can alert you to concepts you didn't think about, and that you may not conceive by yourself in your life time. not because you're not smart, but simply because it won't cross your mind.
it's always good to dedicate a small part of your time to hearing what others have to say, let it be via books, internet or whatever.
i found that the books have much more quality than most internet sites. it's just that when someone writes a book he puts a lot more effort into it, than when he writes a web page.
one thing for sure though - the books won't "teach you to trade". you'll have to teach yourself, or find a proven mentor (those do not market themselves on the internet).